diff --git a/browser/devtools/netmonitor/netmonitor-controller.js b/browser/devtools/netmonitor/netmonitor-controller.js
index 72e7a8a7056..1da4336b5c5 100644
--- a/browser/devtools/netmonitor/netmonitor-controller.js
+++ b/browser/devtools/netmonitor/netmonitor-controller.js
@@ -250,6 +250,7 @@ TargetEventsHandler.prototype = {
       case "will-navigate": {
         // Reset UI.
         NetMonitorView.RequestsMenu.reset();
+        NetMonitorView.Sidebar.reset();
         NetMonitorView.NetworkDetails.reset();
 
         // Reset global helpers cache.
diff --git a/browser/devtools/netmonitor/netmonitor-view.js b/browser/devtools/netmonitor/netmonitor-view.js
index b8437dc6b57..afdd1e59fc4 100644
--- a/browser/devtools/netmonitor/netmonitor-view.js
+++ b/browser/devtools/netmonitor/netmonitor-view.js
@@ -165,7 +165,7 @@ let NetMonitorView = {
     }
 
     if (aTabIndex !== undefined) {
-      $("#details-pane").selectedIndex = aTabIndex;
+      $("#event-details-pane").selectedIndex = aTabIndex;
     }
   },
 
@@ -351,8 +351,63 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
 
     this.refreshSummary();
     this.refreshZebra();
+
+    if (aId == this._preferredItemId) {
+      this.selectedItem = requestItem;
+    }
   },
 
+  /**
+   * Create a new custom request form populated with the data from
+   * the currently selected request.
+   */
+  cloneSelectedRequest: function() {
+    let selected = this.selectedItem.attachment;
+
+    // Create the element node for the network request item.
+    let menuView = this._createMenuView(selected.method, selected.url);
+
+    let newItem = this.push([menuView], {
+      attachment: Object.create(selected, {
+        isCustom: { value: true }
+      })
+    });
+
+    // Immediately switch to new request pane.
+    this.selectedItem = newItem;
+  },
+
+  /**
+   * Send a new HTTP request using the data in the custom request form.
+   */
+  sendCustomRequest: function() {
+    let selected = this.selectedItem.attachment;
+
+    let data = Object.create(selected, {
+      headers: { value: selected.requestHeaders.headers }
+    });
+
+    if (selected.requestPostData) {
+      data.body = selected.requestPostData.postData.text;
+    }
+
+    NetMonitorController.webConsoleClient.sendHTTPRequest(data, (response) => {
+      let id = response.eventActor.actor;
+      this._preferredItemId = id;
+    });
+
+    this.closeCustomRequest();
+  },
+
+  /**
+   * Remove the currently selected custom request.
+   */
+  closeCustomRequest: function() {
+    this.remove(this.selectedItem);
+
+    NetMonitorView.Sidebar.toggle(false);
+   },
+
   /**
    * Filters all network requests in this container by a specified type.
    *
@@ -690,11 +745,11 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
             break;
           case "status":
             requestItem.attachment.status = value;
-            this._updateMenuView(requestItem, key, value);
+            this.updateMenuView(requestItem, key, value);
             break;
           case "statusText":
             requestItem.attachment.statusText = value;
-            this._updateMenuView(requestItem, key,
+            this.updateMenuView(requestItem, key,
               requestItem.attachment.status + " " +
               requestItem.attachment.statusText);
             break;
@@ -703,11 +758,11 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
             break;
           case "contentSize":
             requestItem.attachment.contentSize = value;
-            this._updateMenuView(requestItem, key, value);
+            this.updateMenuView(requestItem, key, value);
             break;
           case "mimeType":
             requestItem.attachment.mimeType = value;
-            this._updateMenuView(requestItem, key, value);
+            this.updateMenuView(requestItem, key, value);
             break;
           case "responseContent":
             requestItem.attachment.responseContent = value;
@@ -715,7 +770,7 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
           case "totalTime":
             requestItem.attachment.totalTime = value;
             requestItem.attachment.endedMillis = requestItem.attachment.startedMillis + value;
-            this._updateMenuView(requestItem, key, value);
+            this.updateMenuView(requestItem, key, value);
             this._registerLastRequestEnd(requestItem.attachment.endedMillis);
             break;
           case "eventTimings":
@@ -757,23 +812,11 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
    *         The network request view.
    */
   _createMenuView: function(aMethod, aUrl) {
-    let uri = nsIURL(aUrl);
-    let nameWithQuery = this._getUriNameWithQuery(uri);
-    let hostPort = this._getUriHostPort(uri);
-
     let template = $("#requests-menu-item-template");
     let fragment = document.createDocumentFragment();
 
-    let method = $(".requests-menu-method", template);
-    method.setAttribute("value", aMethod);
-
-    let file = $(".requests-menu-file", template);
-    file.setAttribute("value", nameWithQuery);
-    file.setAttribute("tooltiptext", nameWithQuery);
-
-    let domain = $(".requests-menu-domain", template);
-    domain.setAttribute("value", hostPort);
-    domain.setAttribute("tooltiptext", hostPort);
+    this.updateMenuView(template, 'method', aMethod);
+    this.updateMenuView(template, 'url', aUrl);
 
     let waterfall = $(".requests-menu-waterfall", template);
     waterfall.style.backgroundImage = this._cachedWaterfallBackground;
@@ -796,22 +839,48 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
    * @param any aValue
    *        The new value to be shown.
    */
-  _updateMenuView: function(aItem, aKey, aValue) {
+  updateMenuView: function(aItem, aKey, aValue) {
+    let target = aItem.target || aItem;
+
     switch (aKey) {
+      case "method": {
+        let node = $(".requests-menu-method", target);
+        node.setAttribute("value", aValue);
+        break;
+      }
+      case "url": {
+        let uri;
+        try {
+          uri = nsIURL(aValue);
+        } catch(e) {
+          break; // User input may not make a well-formed url yet.
+        }
+        let nameWithQuery = this._getUriNameWithQuery(uri);
+        let hostPort = this._getUriHostPort(uri);
+
+        let node = $(".requests-menu-file", target);
+        node.setAttribute("value", nameWithQuery);
+        node.setAttribute("tooltiptext", nameWithQuery);
+
+        let domain = $(".requests-menu-domain", target);
+        domain.setAttribute("value", hostPort);
+        domain.setAttribute("tooltiptext", hostPort);
+        break;
+      }
       case "status": {
-        let node = $(".requests-menu-status", aItem.target);
+        let node = $(".requests-menu-status", target);
         node.setAttribute("code", aValue);
         break;
       }
       case "statusText": {
-        let node = $(".requests-menu-status-and-method", aItem.target);
+        let node = $(".requests-menu-status-and-method", target);
         node.setAttribute("tooltiptext", aValue);
         break;
       }
       case "contentSize": {
         let kb = aValue / 1024;
         let size = L10N.numberWithDecimals(kb, CONTENT_SIZE_DECIMALS);
-        let node = $(".requests-menu-size", aItem.target);
+        let node = $(".requests-menu-size", target);
         let text = L10N.getFormatStr("networkMenu.sizeKB", size);
         node.setAttribute("value", text);
         node.setAttribute("tooltiptext", text);
@@ -819,14 +888,14 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
       }
       case "mimeType": {
         let type = this._getAbbreviatedMimeType(aValue);
-        let node = $(".requests-menu-type", aItem.target);
+        let node = $(".requests-menu-type", target);
         let text = CONTENT_MIME_TYPE_ABBREVIATIONS[type] || type;
         node.setAttribute("value", text);
         node.setAttribute("tooltiptext", aValue);
         break;
       }
       case "totalTime": {
-        let node = $(".requests-menu-timings-total", aItem.target);
+        let node = $(".requests-menu-timings-total", target);
         let text = L10N.getFormatStr("networkMenu.totalMS", aValue); // integer
         node.setAttribute("value", text);
         node.setAttribute("tooltiptext", text);
@@ -1089,10 +1158,10 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
    */
   _onSelect: function({ detail: item }) {
     if (item) {
-      NetMonitorView.NetworkDetails.populate(item.attachment);
-      NetMonitorView.NetworkDetails.toggle(true);
+      NetMonitorView.Sidebar.populate(item.attachment);
+      NetMonitorView.Sidebar.toggle(true);
     } else {
-      NetMonitorView.NetworkDetails.toggle(false);
+      NetMonitorView.Sidebar.toggle(false);
     }
   },
 
@@ -1104,6 +1173,14 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
     drain("resize-events", RESIZE_REFRESH_RATE, () => this._flushWaterfallViews(true));
   },
 
+  /**
+   * Handle the context menu opening. Hide items if no request is selected.
+   */
+  _onContextShowing: function() {
+    let element = $("#request-menu-context-resend");
+    element.hidden = !this.selectedItem || this.selectedItem.attachment.isCustom;
+  },
+
   /**
    * Checks if the specified unix time is the first one to be known of,
    * and saves it if so.
@@ -1239,6 +1316,162 @@ RequestsMenuView.prototype = Heritage.extend(WidgetMethods, {
   _resizeTimeout: null
 });
 
+/**
+ * Functions handling the sidebar details view.
+ */
+function SidebarView() {
+  dumpn("SidebarView was instantiated");
+}
+
+SidebarView.prototype = {
+  /**
+   * Sets this view hidden or visible. It's visible by default.
+   *
+   * @param boolean aVisibleFlag
+   *        Specifies the intended visibility.
+   */
+  toggle: function(aVisibleFlag) {
+    NetMonitorView.toggleDetailsPane({ visible: aVisibleFlag });
+    NetMonitorView.RequestsMenu._flushWaterfallViews(true);
+  },
+
+  /**
+   * Populates this view with the specified data.
+   *
+   * @param object aData
+   *        The data source (this should be the attachment of a request item).
+   */
+  populate: function(aData) {
+    if (aData.isCustom) {
+      NetMonitorView.CustomRequest.populate(aData);
+      $("#details-pane").selectedIndex = 0;
+    } else {
+      NetMonitorView.NetworkDetails.populate(aData);
+      $("#details-pane").selectedIndex = 1;
+    }
+  },
+
+  /**
+   * Hides this container.
+   */
+  reset: function() {
+    this.toggle(false);
+  }
+}
+
+/**
+ * Functions handling the custom request view.
+ */
+function CustomRequestView() {
+  dumpn("CustomRequestView was instantiated");
+}
+
+CustomRequestView.prototype = {
+  /**
+   * Populates this view with the specified data.
+   *
+   * @param object aData
+   *        The data source (this should be the attachment of a request item).
+   */
+  populate: function(aData) {
+    $("#custom-url-value").value = aData.url;
+    $("#custom-method-value").value = aData.method;
+    $("#custom-headers-value").value =
+       writeHeaderText(aData.requestHeaders.headers);
+
+    if (aData.requestPostData) {
+      let body = aData.requestPostData.postData.text;
+
+      gNetwork.getString(body).then((aString) => {
+        $("#custom-postdata-value").value =  aString;
+      });
+    }
+
+    this.updateCustomQuery(aData.url);
+  },
+
+  /**
+   * Handle user input in the custom request form.
+   *
+   * @param object aField
+   *        the field that the user updated.
+   */
+  onUpdate: function(aField) {
+    let selectedItem = NetMonitorView.RequestsMenu.selectedItem;
+    let field = aField;
+    let value;
+
+    switch(aField) {
+      case 'method':
+        value = $("#custom-method-value").value.trim();
+        selectedItem.attachment.method = value;
+        break;
+      case 'url':
+        value = $("#custom-url-value").value;
+        this.updateCustomQuery(value);
+        selectedItem.attachment.url = value;
+        break;
+      case 'query':
+        let query = $("#custom-query-value").value;
+        this.updateCustomUrl(query);
+        field = 'url';
+        value = $("#custom-url-value").value
+        selectedItem.attachment.url = value;
+        break;
+      case 'body':
+        value = $("#custom-postdata-value").value;
+        selectedItem.attachment.requestPostData = {
+          postData: {
+            text: value
+          }
+        };
+        break;
+      case 'headers':
+        let headersText = $("#custom-headers-value").value;
+        value = parseHeaderText(headersText);
+        selectedItem.attachment.requestHeaders = {
+          headers: value
+        };
+        break;
+    }
+
+    NetMonitorView.RequestsMenu.updateMenuView(selectedItem, field, value);
+  },
+
+  /**
+   * Update the query string field based on the url.
+   *
+   * @param object aUrl
+   *        url to extract query string from.
+   */
+  updateCustomQuery: function(aUrl) {
+    let paramsArray = parseQueryString(nsIURL(aUrl).query);
+    if (!paramsArray) {
+      $("#custom-query").hidden = true;
+      return;
+    }
+    $("#custom-query").hidden = false;
+    $("#custom-query-value").value = writeQueryText(paramsArray);
+  },
+
+  /**
+   * Update the url based on the query string field.
+   *
+   * @param object aQueryText
+   *        contents of the query string field.
+   */
+  updateCustomUrl: function(aQueryText) {
+    let params = parseQueryText(aQueryText);
+    let queryString = writeQueryString(params);
+
+    let url = $("#custom-url-value").value;
+    let oldQuery = nsIURL(url).query;
+    let path = url.replace(oldQuery, queryString);
+
+    $("#custom-url-value").value = path;
+  }
+}
+
 /**
  * Functions handling the requests details view.
  */
@@ -1253,9 +1486,9 @@ NetworkDetailsView.prototype = {
    * Initialization function, called when the network monitor is started.
    */
   initialize: function() {
-    dumpn("Initializing the RequestsMenuView");
+    dumpn("Initializing the NetworkDetailsView");
 
-    this.widget = $("#details-pane");
+    this.widget = $("#event-details-pane");
 
     this._headers = new VariablesView($("#all-headers"),
       Heritage.extend(GENERIC_VARIABLES_VIEW_SETTINGS, {
@@ -1292,25 +1525,13 @@ NetworkDetailsView.prototype = {
    * Destruction function, called when the network monitor is closed.
    */
   destroy: function() {
-    dumpn("Destroying the SourcesView");
+    dumpn("Destroying the NetworkDetailsView");
   },
 
   /**
-   * Sets this view hidden or visible. It's visible by default.
-   *
-   * @param boolean aVisibleFlag
-   *        Specifies the intended visibility.
-   */
-  toggle: function(aVisibleFlag) {
-    NetMonitorView.toggleDetailsPane({ visible: aVisibleFlag });
-    NetMonitorView.RequestsMenu._flushWaterfallViews(true);
-  },
-
-  /**
-   * Hides and resets this container (removes all the networking information).
+   * Resets this container (removes all the networking information).
    */
   reset: function() {
-    this.toggle(false);
     this._dataSrc = null;
   },
 
@@ -1581,21 +1802,14 @@ NetworkDetailsView.prototype = {
    *
    * @param string aName
    *        The type of params to populate (get or post).
-   * @param string aParams
+   * @param string aQueryString
    *        A query string of params (e.g. "?foo=bar&baz=42").
    */
-  _addParams: function(aName, aParams) {
-    // Make sure there's at least one param available.
-    if (!aParams || !aParams.contains("=")) {
+  _addParams: function(aName, aQueryString) {
+    let paramsArray = parseQueryString(aQueryString);
+    if (!paramsArray) {
       return;
     }
-    // Turn the params string into an array containing { name: value } tuples.
-    let paramsArray = aParams.replace(/^[?&]/, "").split("&").map((e) =>
-      let (param = e.split("=")) {
-        name: NetworkHelper.convertToUnicode(unescape(param[0])),
-        value: NetworkHelper.convertToUnicode(unescape(param[1]))
-      });
-
     let paramsScope = this._params.addScope(aName);
     paramsScope.expanded = true;
 
@@ -1807,6 +2021,110 @@ function nsIURL(aUrl, aStore = nsIURL.store) {
 }
 nsIURL.store = new Map();
 
+/**
+ * Parse a url's query string into its components
+ *
+ * @param  string aQueryString
+ *         The query part of a url
+ * @return array
+ *         Array of query params {name, value}
+ */
+function parseQueryString(aQueryString) {
+  // Make sure there's at least one param available.
+  if (!aQueryString || !aQueryString.contains("=")) {
+    return;
+  }
+  // Turn the params string into an array containing { name: value } tuples.
+  let paramsArray = aQueryString.replace(/^[?&]/, "").split("&").map((e) =>
+    let (param = e.split("=")) {
+      name: NetworkHelper.convertToUnicode(unescape(param[0])),
+      value: NetworkHelper.convertToUnicode(unescape(param[1]))
+    });
+  return paramsArray;
+}
+
+/**
+ * Parse text representation of HTTP headers.
+ *
+ * @param  string aText
+ *         Text of headers
+ * @return array
+ *         Array of headers info {name, value}
+ */
+function parseHeaderText(aText) {
+  return parseRequestText(aText, ":");
+}
+
+/**
+ * Parse readable text list of a query string.
+ *
+ * @param  string aText
+ *         Text of query string represetation
+ * @return array
+ *         Array of query params {name, value}
+ */
+function parseQueryText(aText) {
+  return parseRequestText(aText, "=");
+}
+
+/**
+ * Parse a text representation of a name:value list with
+ * the given name:value divider character.
+ *
+ * @param  string aText
+ *         Text of list
+ * @return array
+ *         Array of headers info {name, value}
+ */
+function parseRequestText(aText, aDivider) {
+  let regex = new RegExp("(.+?)\\" + aDivider + "\\s*(.+)");
+  let pairs = [];
+  for (let line of aText.split("\n")) {
+    let matches;
+    if (matches = regex.exec(line)) {
+      let [, name, value] = matches;
+      pairs.push({name: name, value: value});
+    }
+  }
+  return pairs;
+}
+
+/**
+ * Write out a list of headers into a chunk of text
+ *
+ * @param array aHeaders
+ *        Array of headers info {name, value}
+ * @return string aText
+ *         List of headers in text format
+ */
+function writeHeaderText(aHeaders) {
+  return [(name + ": " + value) for ({name, value} of aHeaders)].join("\n");
+}
+
+/**
+ * Write out a list of query params into a chunk of text
+ *
+ * @param array aParams
+ *        Array of query params {name, value}
+ * @return string
+ *         List of query params in text format
+ */
+function writeQueryText(aParams) {
+  return [(name + "=" + value) for ({name, value} of aParams)].join("\n");
+}
+
+/**
+ * Write out a list of query params into a query string
+ *
+ * @param array aParams
+ *        Array of query  params {name, value}
+ * @return string
+ *         Query string that can be appended to a url.
+ */
+function writeQueryString(aParams) {
+  return [(name + "=" + value) for ({name, value} of aParams)].join("&");
+}
+
 /**
  * Helper for draining a rapid succession of events and invoking a callback
  * once everything settles down.
@@ -1822,4 +2140,6 @@ drain.store = new Map();
  */
 NetMonitorView.Toolbar = new ToolbarView();
 NetMonitorView.RequestsMenu = new RequestsMenuView();
+NetMonitorView.Sidebar = new SidebarView();
+NetMonitorView.CustomRequest = new CustomRequestView();
 NetMonitorView.NetworkDetails = new NetworkDetailsView();
diff --git a/browser/devtools/netmonitor/netmonitor.css b/browser/devtools/netmonitor/netmonitor.css
index cae41f8aa2e..ce087d7dca1 100644
--- a/browser/devtools/netmonitor/netmonitor.css
+++ b/browser/devtools/netmonitor/netmonitor.css
@@ -15,6 +15,10 @@
   overflow: auto;
 }
 
+#custom-pane {
+  overflow: auto;
+}
+
 #timings-summary-blocked {
   display: none; /* This doesn't work yet. */
 }
diff --git a/browser/devtools/netmonitor/netmonitor.xul b/browser/devtools/netmonitor/netmonitor.xul
index 06f4f1e09ec..48165c5376f 100644
--- a/browser/devtools/netmonitor/netmonitor.xul
+++ b/browser/devtools/netmonitor/netmonitor.xul
@@ -17,6 +17,16 @@
   <script type="text/javascript" src="netmonitor-controller.js"/>
   <script type="text/javascript" src="netmonitor-view.js"/>
 
+  <popupset id="networkPopupSet">
+    <menupopup id="network-request-popup"
+               onpopupshowing="NetMonitorView.RequestsMenu._onContextShowing(event);">
+      <menuitem id="request-menu-context-resend"
+                label="&netmonitorUI.summary.resend;"
+                accesskey="&netmonitorUI.summary.resend.accesskey;"
+                oncommand="NetMonitorView.RequestsMenu.cloneSelectedRequest();"/>
+    </menupopup>
+  </popupset>
+
   <box id="body"
        class="devtools-responsive-container"
        flex="1">
@@ -103,7 +113,7 @@
       </toolbar>
       <label id="requests-menu-empty-notice"
              value="&netmonitorUI.emptyNotice2;"/>
-      <vbox id="requests-menu-contents" flex="1">
+      <vbox id="requests-menu-contents" flex="1" context="network-request-popup">
         <hbox id="requests-menu-item-template" hidden="true">
           <hbox class="requests-menu-subitem requests-menu-status-and-method"
                 align="center">
@@ -194,184 +204,251 @@
 
     <splitter class="devtools-side-splitter"/>
 
-    <tabbox id="details-pane"
-            class="devtools-sidebar-tabs"
-            hidden="true">
-      <tabs>
-        <tab label="&netmonitorUI.tab.headers;"/>
-        <tab label="&netmonitorUI.tab.cookies;"/>
-        <tab label="&netmonitorUI.tab.params;"/>
-        <tab label="&netmonitorUI.tab.response;"/>
-        <tab label="&netmonitorUI.tab.timings;"/>
-      </tabs>
-      <tabpanels flex="1">
-        <tabpanel id="headers-tabppanel"
-                  class="tabpanel-content">
-          <vbox flex="1">
-            <hbox id="headers-summary-url"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.summary.url;"/>
-              <label id="headers-summary-url-value"
-                     class="plain tabpanel-summary-value"
-                     crop="end"
-                     flex="1"/>
-            </hbox>
-            <hbox id="headers-summary-method"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.summary.method;"/>
-              <label id="headers-summary-method-value"
-                     class="plain tabpanel-summary-value"
-                     crop="end"
-                     flex="1"/>
-            </hbox>
-            <hbox id="headers-summary-status"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.summary.status;"/>
-              <box id="headers-summary-status-circle"
-                   class="requests-menu-status"/>
-              <label id="headers-summary-status-value"
-                     class="plain tabpanel-summary-value"
-                     crop="end"
-                     flex="1"/>
-            </hbox>
-            <hbox id="headers-summary-version"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.summary.version;"/>
-              <label id="headers-summary-version-value"
-                     class="plain tabpanel-summary-value"
-                     crop="end"
-                     flex="1"/>
-            </hbox>
-            <vbox id="all-headers" flex="1"/>
-          </vbox>
-        </tabpanel>
-        <tabpanel id="cookies-tabpanel"
-                  class="tabpanel-content">
-          <vbox flex="1">
-            <vbox id="all-cookies" flex="1"/>
-          </vbox>
-        </tabpanel>
-        <tabpanel id="params-tabpanel"
-                  class="tabpanel-content">
-          <vbox flex="1">
-            <vbox id="request-params-box" flex="1" hidden="true">
-              <vbox id="request-params" flex="1"/>
-            </vbox>
-            <vbox id="request-post-data-textarea-box" flex="1" hidden="true">
-              <vbox id="request-post-data-textarea" flex="1"/>
-            </vbox>
-          </vbox>
-        </tabpanel>
-        <tabpanel id="response-tabpanel"
-                  class="tabpanel-content">
-          <vbox flex="1">
-            <label id="response-content-info-header"/>
-            <vbox id="response-content-json-box" flex="1" hidden="true">
-              <vbox id="response-content-json" flex="1"/>
-            </vbox>
-            <vbox id="response-content-textarea-box" flex="1" hidden="true">
-              <vbox id="response-content-textarea" flex="1"/>
-            </vbox>
-            <vbox id="response-content-image-box" flex="1" hidden="true">
-              <image id="response-content-image"/>
-              <hbox>
+    <deck id="details-pane"
+          hidden="true">
+      <vbox id="custom-pane"
+            class="tabpanel-content">
+        <hbox align="baseline">
+          <label value="&netmonitorUI.custom.newRequest;"
+                 class="plain tabpanel-summary-label
+                        custom-header"/>
+          <hbox flex="1" pack="end">
+            <button class="devtools-toolbarbutton"
+                    label="&netmonitorUI.custom.send;"
+                    onclick="NetMonitorView.RequestsMenu.sendCustomRequest();"/>
+            <button class="devtools-toolbarbutton"
+                    label="&netmonitorUI.custom.cancel;"
+                    onclick="NetMonitorView.RequestsMenu.closeCustomRequest();"/>
+          </hbox>
+        </hbox>
+        <hbox id="custom-method-and-url"
+              class="tabpanel-summary-container"
+              align="center">
+          <textbox id="custom-method-value"
+                   oninput="NetMonitorView.CustomRequest.onUpdate('method');"
+                   multiline="true"
+                   cols="6"
+                   rows="1"/>
+          <textbox id="custom-url-value"
+                   flex="1"
+                   oninput="NetMonitorView.CustomRequest.onUpdate('url');"/>
+        </hbox>
+        <vbox id="custom-query"
+              class="tabpanel-summary-container custom-section">
+          <label class="plain tabpanel-summary-label"
+                 value="&netmonitorUI.custom.query;"/>
+          <textbox id="custom-query-value"
+                   class="tabpanel-summary-input"
+                   multiline="true"
+                   rows="4"
+                   wrap="off"
+                   oninput="NetMonitorView.CustomRequest.onUpdate('query');"/>
+        </vbox>
+        <vbox id="custom-headers"
+              class="tabpanel-summary-container custom-section">
+          <label class="plain tabpanel-summary-label"
+                 value="&netmonitorUI.custom.headers;"/>
+          <textbox id="custom-headers-value"
+                   class="tabpanel-summary-input"
+                   multiline="true"
+                   rows="6"
+                   wrap="off"
+                   oninput="NetMonitorView.CustomRequest.onUpdate('headers');"/>
+        </vbox>
+        <vbox id="custom-postdata"
+              class="tabpanel-summary-container custom-section">
+          <label class="plain tabpanel-summary-label"
+                 value="&netmonitorUI.custom.postData;"/>
+          <textbox id="custom-postdata-value"
+                   class="tabpanel-summary-input"
+                   multiline="true"
+                   rows="6"
+                   wrap="off"
+                   oninput="NetMonitorView.CustomRequest.onUpdate('body');"/>
+        </vbox>
+      </vbox>
+      <tabbox id="event-details-pane"
+              class="devtools-sidebar-tabs">
+        <tabs>
+          <tab label="&netmonitorUI.tab.headers;"/>
+          <tab label="&netmonitorUI.tab.cookies;"/>
+          <tab label="&netmonitorUI.tab.params;"/>
+          <tab label="&netmonitorUI.tab.response;"/>
+          <tab label="&netmonitorUI.tab.timings;"/>
+        </tabs>
+        <tabpanels flex="1">
+          <tabpanel id="headers-tabppanel"
+                    class="tabpanel-content">
+            <vbox flex="1">
+              <hbox id="headers-summary-url"
+                    class="tabpanel-summary-container"
+                    align="center">
                 <label class="plain tabpanel-summary-label"
-                       value="&netmonitorUI.response.name;"/>
-                <label id="response-content-image-name-value"
+                       value="&netmonitorUI.summary.url;"/>
+                <label id="headers-summary-url-value"
                        class="plain tabpanel-summary-value"
                        crop="end"
                        flex="1"/>
               </hbox>
-              <hbox>
+              <hbox id="headers-summary-method"
+                    class="tabpanel-summary-container"
+                    align="center">
                 <label class="plain tabpanel-summary-label"
-                       value="&netmonitorUI.response.dimensions;"/>
-                <label id="response-content-image-dimensions-value"
+                       value="&netmonitorUI.summary.method;"/>
+                <label id="headers-summary-method-value"
                        class="plain tabpanel-summary-value"
                        crop="end"
                        flex="1"/>
               </hbox>
-              <hbox>
+              <hbox id="headers-summary-status"
+                    class="tabpanel-summary-container"
+                    align="center">
                 <label class="plain tabpanel-summary-label"
-                       value="&netmonitorUI.response.mime;"/>
-                <label id="response-content-image-mime-value"
+                       value="&netmonitorUI.summary.status;"/>
+                <box id="headers-summary-status-circle"
+                     class="requests-menu-status"/>
+                <label id="headers-summary-status-value"
+                       class="plain tabpanel-summary-value"
+                       crop="end"
+                       flex="1"/>
+                <button id="headers-summary-resend"
+                       label="&netmonitorUI.summary.resend;"
+                       class="devtools-toolbarbutton"
+                       onclick="NetMonitorView.RequestsMenu.cloneSelectedRequest();"/>
+              </hbox>
+              <hbox id="headers-summary-version"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.summary.version;"/>
+                <label id="headers-summary-version-value"
                        class="plain tabpanel-summary-value"
                        crop="end"
                        flex="1"/>
               </hbox>
-              <hbox>
+              <vbox id="all-headers" flex="1"/>
+            </vbox>
+          </tabpanel>
+          <tabpanel id="cookies-tabpanel"
+                    class="tabpanel-content">
+            <vbox flex="1">
+              <vbox id="all-cookies" flex="1"/>
+            </vbox>
+          </tabpanel>
+          <tabpanel id="params-tabpanel"
+                    class="tabpanel-content">
+            <vbox flex="1">
+              <vbox id="request-params-box" flex="1" hidden="true">
+                <vbox id="request-params" flex="1"/>
+              </vbox>
+              <vbox id="request-post-data-textarea-box" flex="1" hidden="true">
+                <vbox id="request-post-data-textarea" flex="1"/>
+              </vbox>
+            </vbox>
+          </tabpanel>
+          <tabpanel id="response-tabpanel"
+                    class="tabpanel-content">
+            <vbox flex="1">
+              <label id="response-content-info-header"/>
+              <vbox id="response-content-json-box" flex="1" hidden="true">
+                <vbox id="response-content-json" flex="1"/>
+              </vbox>
+              <vbox id="response-content-textarea-box" flex="1" hidden="true">
+                <vbox id="response-content-textarea" flex="1"/>
+              </vbox>
+              <vbox id="response-content-image-box" flex="1" hidden="true">
+                <image id="response-content-image"/>
+                <hbox>
+                  <label class="plain tabpanel-summary-label"
+                         value="&netmonitorUI.response.name;"/>
+                  <label id="response-content-image-name-value"
+                         class="plain tabpanel-summary-value"
+                         crop="end"
+                         flex="1"/>
+                </hbox>
+                <hbox>
+                  <label class="plain tabpanel-summary-label"
+                         value="&netmonitorUI.response.dimensions;"/>
+                  <label id="response-content-image-dimensions-value"
+                         class="plain tabpanel-summary-value"
+                         crop="end"
+                         flex="1"/>
+                </hbox>
+                <hbox>
+                  <label class="plain tabpanel-summary-label"
+                         value="&netmonitorUI.response.mime;"/>
+                  <label id="response-content-image-mime-value"
+                         class="plain tabpanel-summary-value"
+                         crop="end"
+                         flex="1"/>
+                </hbox>
+                <hbox>
+                  <label class="plain tabpanel-summary-label"
+                         value="&netmonitorUI.response.encoding;"/>
+                  <label id="response-content-image-encoding-value"
+                         class="plain tabpanel-summary-value"
+                         crop="end"
+                         flex="1"/>
+                </hbox>
+              </vbox>
+            </vbox>
+          </tabpanel>
+          <tabpanel id="timings-tabpanel"
+                    class="tabpanel-content">
+            <vbox flex="1">
+              <hbox id="timings-summary-blocked"
+                    class="tabpanel-summary-container"
+                    align="center">
                 <label class="plain tabpanel-summary-label"
-                       value="&netmonitorUI.response.encoding;"/>
-                <label id="response-content-image-encoding-value"
-                       class="plain tabpanel-summary-value"
-                       crop="end"
-                       flex="1"/>
+                       value="&netmonitorUI.timings.blocked;"/>
+                <hbox class="requests-menu-timings-box blocked"/>
+                <label class="plain requests-menu-timings-total"/>
+              </hbox>
+              <hbox id="timings-summary-dns"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.timings.dns;"/>
+                <hbox class="requests-menu-timings-box dns"/>
+                <label class="plain requests-menu-timings-total"/>
+              </hbox>
+              <hbox id="timings-summary-connect"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.timings.connect;"/>
+                <hbox class="requests-menu-timings-box connect"/>
+                <label class="plain requests-menu-timings-total"/>
+              </hbox>
+              <hbox id="timings-summary-send"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.timings.send;"/>
+                <hbox class="requests-menu-timings-box send"/>
+                <label class="plain requests-menu-timings-total"/>
+              </hbox>
+              <hbox id="timings-summary-wait"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.timings.wait;"/>
+                <hbox class="requests-menu-timings-box wait"/>
+                <label class="plain requests-menu-timings-total"/>
+              </hbox>
+              <hbox id="timings-summary-receive"
+                    class="tabpanel-summary-container"
+                    align="center">
+                <label class="plain tabpanel-summary-label"
+                       value="&netmonitorUI.timings.receive;"/>
+                <hbox class="requests-menu-timings-box receive"/>
+                <label class="plain requests-menu-timings-total"/>
               </hbox>
             </vbox>
-          </vbox>
-        </tabpanel>
-        <tabpanel id="timings-tabpanel"
-                  class="tabpanel-content">
-          <vbox flex="1">
-            <hbox id="timings-summary-blocked"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.blocked;"/>
-              <hbox class="requests-menu-timings-box blocked"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-            <hbox id="timings-summary-dns"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.dns;"/>
-              <hbox class="requests-menu-timings-box dns"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-            <hbox id="timings-summary-connect"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.connect;"/>
-              <hbox class="requests-menu-timings-box connect"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-            <hbox id="timings-summary-send"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.send;"/>
-              <hbox class="requests-menu-timings-box send"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-            <hbox id="timings-summary-wait"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.wait;"/>
-              <hbox class="requests-menu-timings-box wait"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-            <hbox id="timings-summary-receive"
-                  class="tabpanel-summary-container"
-                  align="center">
-              <label class="plain tabpanel-summary-label"
-                     value="&netmonitorUI.timings.receive;"/>
-              <hbox class="requests-menu-timings-box receive"/>
-              <label class="plain requests-menu-timings-total"/>
-            </hbox>
-          </vbox>
-        </tabpanel>
-      </tabpanels>
-    </tabbox>
+          </tabpanel>
+        </tabpanels>
+      </tabbox>
+    </deck>
   </box>
 
 </window>
diff --git a/browser/devtools/netmonitor/test/Makefile.in b/browser/devtools/netmonitor/test/Makefile.in
index 0fcd2e895ad..6d238a9bda9 100644
--- a/browser/devtools/netmonitor/test/Makefile.in
+++ b/browser/devtools/netmonitor/test/Makefile.in
@@ -42,6 +42,7 @@ MOCHITEST_BROWSER_TESTS = \
 	browser_net_accessibility-01.js \
 	browser_net_accessibility-02.js \
 	browser_net_footer-summary.js \
+	browser_net_resend.js \
 	head.js \
 	$(NULL)
 
diff --git a/browser/devtools/netmonitor/test/browser_net_post-data-02.js b/browser/devtools/netmonitor/test/browser_net_post-data-02.js
index 305f31b7185..c60550af560 100644
--- a/browser/devtools/netmonitor/test/browser_net_post-data-02.js
+++ b/browser/devtools/netmonitor/test/browser_net_post-data-02.js
@@ -20,8 +20,8 @@ function test() {
       NetMonitorView.toggleDetailsPane({ visible: true }, 2)
       RequestsMenu.selectedIndex = 0;
 
-      let tab = document.querySelectorAll("#details-pane tab")[2];
-      let tabpanel = document.querySelectorAll("#details-pane tabpanel")[2];
+      let tab = document.querySelectorAll("#event-details-pane tab")[2];
+      let tabpanel = document.querySelectorAll("#event-details-pane tabpanel")[2];
 
       is(tab.getAttribute("selected"), "true",
         "The params tab in the network details pane should be selected.");
diff --git a/browser/devtools/netmonitor/test/browser_net_resend.js b/browser/devtools/netmonitor/test/browser_net_resend.js
new file mode 100644
index 00000000000..2d9b52acd9b
--- /dev/null
+++ b/browser/devtools/netmonitor/test/browser_net_resend.js
@@ -0,0 +1,167 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+let gPanelWin;
+let gPanelDoc;
+
+const ADD_QUERY = "t1=t2";
+const ADD_HEADER = "Test-header: true";
+const ADD_POSTDATA = "t3=t4";
+
+/**
+ * Tests if resending a request works.
+ */
+
+function test() {
+  initNetMonitor(POST_DATA_URL).then(([aTab, aDebuggee, aMonitor]) => {
+    info("Starting test... ");
+
+    gPanelWin = aMonitor.panelWin;
+    gPanelDoc = gPanelWin.document;
+
+    let { NetMonitorView } = gPanelWin;
+    let { RequestsMenu } = NetMonitorView;
+
+    RequestsMenu.lazyUpdate = false;
+
+    waitForNetworkEvents(aMonitor, 0, 2).then(() => {
+      let origItem = RequestsMenu.getItemAtIndex(0);
+      RequestsMenu.selectedItem = origItem;
+
+      // add a new custom request cloned from selected request
+      RequestsMenu.cloneSelectedRequest();
+      testCustomForm(origItem.attachment);
+
+      let customItem = RequestsMenu.selectedItem;
+      testCustomItem(customItem, origItem);
+
+      // edit the custom request
+      editCustomForm(() => {
+        testCustomItemChanged(customItem, origItem);
+
+        waitForNetworkEvents(aMonitor, 0, 1).then(() => {
+          let sentItem = RequestsMenu.selectedItem;
+          testSentRequest(sentItem.attachment, origItem.attachment);
+          finishUp(aMonitor);
+        });
+        // send the new request
+        RequestsMenu.sendCustomRequest();
+      });
+    });
+
+    aDebuggee.performRequests();
+  });
+}
+
+function testCustomItem(aItem, aOrigItem) {
+  let method = aItem.target.querySelector(".requests-menu-method").value;
+  let origMethod = aOrigItem.target.querySelector(".requests-menu-method").value;
+  is(method, origMethod, "menu item is showing the same method as original request");
+
+  let file = aItem.target.querySelector(".requests-menu-file").value;
+  let origFile = aOrigItem.target.querySelector(".requests-menu-file").value;
+  is(file, origFile, "menu item is showing the same file name as original request");
+
+  let domain = aItem.target.querySelector(".requests-menu-domain").value;
+  let origDomain = aOrigItem.target.querySelector(".requests-menu-domain").value;
+  is(domain, origDomain, "menu item is showing the same domain as original request");
+}
+
+function testCustomItemChanged(aItem, aOrigItem) {
+  let file = aItem.target.querySelector(".requests-menu-file").value;
+  let expectedFile = aOrigItem.target.querySelector(".requests-menu-file").value + "&" + ADD_QUERY;
+
+  is(file, expectedFile, "menu item is updated to reflect url entered in form");
+}
+
+/*
+ * Test that the New Request form was populated correctly
+ */
+function testCustomForm(aData) {
+  is(gPanelDoc.getElementById("custom-method-value").value, aData.method,
+     "new request form showing correct method");
+
+  is(gPanelDoc.getElementById("custom-url-value").value, aData.url,
+     "new request form showing correct url");
+
+  let query = gPanelDoc.getElementById("custom-query-value");
+  is(query.value, "foo=bar\nbaz=42\ntype=urlencoded",
+     "new request form showing correct query string");
+
+  let headers = gPanelDoc.getElementById("custom-headers-value").value.split("\n");
+  for (let {name, value} of aData.requestHeaders.headers) {
+    ok(headers.indexOf(name + ": " + value) >= 0, "form contains header from request");
+  }
+
+  let postData = gPanelDoc.getElementById("custom-postdata-value");
+  is(postData.value, aData.requestPostData.postData.text,
+     "new request form showing correct post data");
+}
+
+/*
+ * Add some params and headers to the request form
+ */
+function editCustomForm(callback) {
+  gPanelWin.focus();
+
+  let query = gPanelDoc.getElementById("custom-query-value");
+  query.addEventListener("focus", function onFocus() {
+    query.removeEventListener("focus", onFocus, false);
+
+    // add params to url query string field
+    type(["VK_RETURN"]);
+    type(ADD_QUERY);
+
+    let headers = gPanelDoc.getElementById("custom-headers-value");
+    headers.addEventListener("focus", function onFocus() {
+      headers.removeEventListener("focus", onFocus, false);
+
+      // add a header
+      type(["VK_RETURN"]);
+      type(ADD_HEADER);
+
+      let postData = gPanelDoc.getElementById("custom-postdata-value");
+      postData.addEventListener("focus", function onFocus() {
+        postData.removeEventListener("focus", onFocus, false);
+
+        // add to POST data
+        type(ADD_POSTDATA);
+        callback();
+      }, false);
+      postData.focus();
+    }, false);
+    headers.focus();
+  }, false);
+  query.focus();
+}
+
+/*
+ * Make sure newly created event matches expected request
+ */
+function testSentRequest(aData, aOrigData) {
+  is(aData.method, aOrigData.method, "correct method in sent request");
+  is(aData.url, aOrigData.url + "&" + ADD_QUERY, "correct url in sent request");
+
+  let hasHeader = aData.requestHeaders.headers.some((header) => {
+    return (header.name + ": " + header.value) == ADD_HEADER;
+  })
+  ok(hasHeader, "new header added to sent request");
+
+  is(aData.requestPostData.postData.text,
+     aOrigData.requestPostData.postData.text + ADD_POSTDATA,
+     "post data added to sent request");
+}
+
+
+function type(aString) {
+  for (let ch of aString) {
+    EventUtils.synthesizeKey(ch, {}, gPanelWin);
+  }
+}
+
+function finishUp(aMonitor) {
+  gPanelWin = null;
+  gPanelDoc = null;
+
+  teardown(aMonitor).then(finish);
+}
diff --git a/browser/locales/en-US/chrome/browser/devtools/netmonitor.dtd b/browser/locales/en-US/chrome/browser/devtools/netmonitor.dtd
index bdf28c90c9b..79654af2a53 100644
--- a/browser/locales/en-US/chrome/browser/devtools/netmonitor.dtd
+++ b/browser/locales/en-US/chrome/browser/devtools/netmonitor.dtd
@@ -168,3 +168,36 @@
   -  in the network details timings tab identifying the amount of time spent
   -  in a "receive" state. -->
 <!ENTITY netmonitorUI.timings.receive     "Receiving:">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the label displayed
+  -  on the button in the headers tab that opens a form to resend the currently
+     displayed request -->
+<!ENTITY netmonitorUI.summary.resend      "Resend">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the access key
+  -  for the Resend menu item displayed in the context menu for a request -->
+<!ENTITY netmonitorUI.summary.resend.accesskey  "R">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.newRequest): This is the label displayed
+  -  as the title of the new custom request form -->
+<!ENTITY netmonitorUI.custom.newRequest   "New Request">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.query): This is the label displayed
+  -  above the query string entry in the custom request form -->
+<!ENTITY netmonitorUI.custom.query        "Query String:">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the label displayed
+  -  above the request headers entry in the custom request form -->
+<!ENTITY netmonitorUI.custom.headers      "Request Headers:">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the label displayed
+  -  above the request body entry in the custom request form -->
+<!ENTITY netmonitorUI.custom.postData     "Request Body:">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the label displayed
+  -  on the button which sends the custom request -->
+<!ENTITY netmonitorUI.custom.send         "Send">
+
+<!-- LOCALIZATION NOTE (debuggerUI.custom.headers): This is the label displayed
+  -  on the button which cancels and closes the custom request form -->
+<!ENTITY netmonitorUI.custom.cancel       "Cancel">
diff --git a/browser/themes/linux/devtools/netmonitor.css b/browser/themes/linux/devtools/netmonitor.css
index a93106ca32e..59a2854009c 100644
--- a/browser/themes/linux/devtools/netmonitor.css
+++ b/browser/themes/linux/devtools/netmonitor.css
@@ -383,6 +383,11 @@ box.requests-menu-status[code^="5"] {
   padding-top: 2px;
 }
 
+#headers-summary-resend {
+  margin: 0 6px;
+  min-height: 20px;
+}
+
 /* Response tabpanel */
 
 #response-content-info-header {
@@ -422,6 +427,20 @@ box.requests-menu-status[code^="5"] {
   transition: transform 0.2s ease-out;
 }
 
+/* Custom request form */
+
+#custom-pane {
+  padding: 0.6em 0.5em;
+}
+
+.custom-header {
+  font-size: 1.1em;
+}
+
+.custom-section {
+  margin-top: 0.5em;
+}
+
 /* Footer */
 
 #requests-menu-footer {
diff --git a/browser/themes/osx/devtools/netmonitor.css b/browser/themes/osx/devtools/netmonitor.css
index 906ae13feea..ad31a365888 100644
--- a/browser/themes/osx/devtools/netmonitor.css
+++ b/browser/themes/osx/devtools/netmonitor.css
@@ -383,6 +383,11 @@ box.requests-menu-status[code^="5"] {
   padding-top: 2px;
 }
 
+#headers-summary-resend {
+  margin: 0 6px;
+  min-height: 20px;
+}
+
 /* Response tabpanel */
 
 #response-content-info-header {
@@ -422,6 +427,20 @@ box.requests-menu-status[code^="5"] {
   transition: transform 0.2s ease-out;
 }
 
+/* Custom request form */
+
+#custom-pane {
+  padding: 0.6em 0.5em;
+}
+
+.custom-header {
+  font-size: 1.1em;
+}
+
+.custom-section {
+  margin-top: 0.5em;
+}
+
 /* Footer */
 
 #requests-menu-footer {
diff --git a/browser/themes/windows/devtools/netmonitor.css b/browser/themes/windows/devtools/netmonitor.css
index ee72aa607a4..1dc29e0676d 100644
--- a/browser/themes/windows/devtools/netmonitor.css
+++ b/browser/themes/windows/devtools/netmonitor.css
@@ -383,6 +383,11 @@ box.requests-menu-status[code^="5"] {
   padding-top: 2px;
 }
 
+#headers-summary-resend {
+  margin: 0 6px;
+  min-height: 20px;
+}
+
 /* Response tabpanel */
 
 #response-content-info-header {
@@ -422,6 +427,20 @@ box.requests-menu-status[code^="5"] {
   transition: transform 0.2s ease-out;
 }
 
+/* Custom request form */
+
+#custom-pane {
+  padding: 0.6em 0.5em;
+}
+
+.custom-header {
+  font-size: 1.1em;
+}
+
+.custom-section {
+  margin-top: 0.5em;
+}
+
 /* Footer */
 
 #requests-menu-footer {
diff --git a/toolkit/devtools/server/actors/webconsole.js b/toolkit/devtools/server/actors/webconsole.js
index 82a16a4e492..3f64d30eeb4 100644
--- a/toolkit/devtools/server/actors/webconsole.js
+++ b/toolkit/devtools/server/actors/webconsole.js
@@ -89,6 +89,7 @@ function WebConsoleActor(aConnection, aParentActor)
 
   this._protoChains = new Map();
   this._dbgGlobals = new Map();
+  this._netEvents = new Map();
   this._getDebuggerGlobal(this.window);
 
   this._onObserverNotification = this._onObserverNotification.bind(this);
@@ -147,6 +148,15 @@ WebConsoleActor.prototype =
    */
   _dbgGlobals: null,
 
+  /**
+   * Holds a map between nsIChannel objects and NetworkEventActors for requests
+   * created with sendHTTPRequest.
+   *
+   * @private
+   * @type Map
+   */
+  _netEvents: null,
+
   /**
    * Object that holds the JSTerm API, the helper functions, for the default
    * window object.
@@ -252,6 +262,8 @@ WebConsoleActor.prototype =
                                   "last-pb-context-exited");
     }
     this._actorPool = null;
+
+    this._netEvents.clear();
     this._protoChains.clear();
     this._dbgGlobals.clear();
     this._jstermHelpers = null;
@@ -1000,10 +1012,10 @@ WebConsoleActor.prototype =
    *         A new NetworkEventActor is returned. This is used for tracking the
    *         network request and response.
    */
-  onNetworkEvent: function WCA_onNetworkEvent(aEvent)
+  onNetworkEvent: function WCA_onNetworkEvent(aEvent, aChannel)
   {
-    let actor = new NetworkEventActor(aEvent, this);
-    this._actorPool.addActor(actor);
+    let actor = this.getNetworkEventActor(aChannel);
+    actor.init(aEvent);
 
     let packet = {
       from: this.actorID,
@@ -1016,6 +1028,57 @@ WebConsoleActor.prototype =
     return actor;
   },
 
+  /**
+   * Get the NetworkEventActor for a nsIChannel, if it exists,
+   * otherwise create a new one.
+   *
+   * @param object aChannel
+   *        The channel for the network event.
+   */
+  getNetworkEventActor: function WCA_getNetworkEventActor(aChannel) {
+    let actor = this._netEvents.get(aChannel);
+    if (actor) {
+      // delete from map as we should only need to do this check once
+      this._netEvents.delete(aChannel);
+      actor.channel = null;
+      return actor;
+    }
+
+    actor = new NetworkEventActor(aChannel, this);
+    this._actorPool.addActor(actor);
+    return actor;
+  },
+
+  /**
+   * Send a new HTTP request from the target's window.
+   *
+   * @param object aMessage
+   *        Object with 'request' - the HTTP request details.
+   */
+  onSendHTTPRequest: function WCA_onSendHTTPRequest(aMessage)
+  {
+    let details = aMessage.request;
+
+    // send request from target's window
+    let request = new this._window.XMLHttpRequest();
+    request.open(details.method, details.url, true);
+
+    for (let {name, value} of details.headers) {
+      request.setRequestHeader(name, value);
+    }
+    request.send(details.body);
+
+    let actor = this.getNetworkEventActor(request.channel);
+
+    // map channel to actor so we can associate future events with it
+    this._netEvents.set(request.channel, actor);
+
+    return {
+      from: this.actorID,
+      eventActor: actor.grip()
+    };
+  },
+
   /**
    * Handler for file activity. This method sends the file request information
    * to the remote Web Console client.
@@ -1113,7 +1176,7 @@ WebConsoleActor.prototype =
         });
         break;
     }
-  },
+  }
 };
 
 WebConsoleActor.prototype.requestTypes =
@@ -1125,32 +1188,31 @@ WebConsoleActor.prototype.requestTypes =
   autocomplete: WebConsoleActor.prototype.onAutocomplete,
   clearMessagesCache: WebConsoleActor.prototype.onClearMessagesCache,
   setPreferences: WebConsoleActor.prototype.onSetPreferences,
+  sendHTTPRequest: WebConsoleActor.prototype.onSendHTTPRequest
 };
 
 /**
  * Creates an actor for a network event.
  *
  * @constructor
- * @param object aNetworkEvent
- *        The network event you want to use the actor for.
+ * @param object aChannel
+ *        The nsIChannel associated with this event.
  * @param object aWebConsoleActor
  *        The parent WebConsoleActor instance for this object.
  */
-function NetworkEventActor(aNetworkEvent, aWebConsoleActor)
+function NetworkEventActor(aChannel, aWebConsoleActor)
 {
   this.parent = aWebConsoleActor;
   this.conn = this.parent.conn;
-
-  this._startedDateTime = aNetworkEvent.startedDateTime;
-  this._isXHR = aNetworkEvent.isXHR;
+  this.channel = aChannel;
 
   this._request = {
-    method: aNetworkEvent.method,
-    url: aNetworkEvent.url,
-    httpVersion: aNetworkEvent.httpVersion,
+    method: null,
+    url: null,
+    httpVersion: null,
     headers: [],
     cookies: [],
-    headersSize: aNetworkEvent.headersSize,
+    headersSize: null,
     postData: {},
   };
 
@@ -1164,10 +1226,6 @@ function NetworkEventActor(aNetworkEvent, aWebConsoleActor)
 
   // Keep track of LongStringActors owned by this NetworkEventActor.
   this._longStringActors = new Set();
-
-  this._discardRequestBody = aNetworkEvent.discardRequestBody;
-  this._discardResponseBody = aNetworkEvent.discardResponseBody;
-  this._private = aNetworkEvent.private;
 }
 
 NetworkEventActor.prototype =
@@ -1206,6 +1264,10 @@ NetworkEventActor.prototype =
       }
     }
     this._longStringActors = new Set();
+
+    if (this.channel) {
+      this.parent._netEvents.delete(this.channel);
+    }
     this.parent.releaseActor(this);
   },
 
@@ -1218,6 +1280,27 @@ NetworkEventActor.prototype =
     return {};
   },
 
+  /**
+   * Set the properties of this actor based on it's corresponding
+   * network event.
+   *
+   * @param object aNetworkEvent
+   *        The network event associated with this actor.
+   */
+  init: function NEA_init(aNetworkEvent)
+  {
+    this._startedDateTime = aNetworkEvent.startedDateTime;
+    this._isXHR = aNetworkEvent.isXHR;
+
+    for (let prop of ['method', 'url', 'httpVersion', 'headersSize']) {
+      this._request[prop] = aNetworkEvent[prop];
+    }
+
+    this._discardRequestBody = aNetworkEvent.discardRequestBody;
+    this._discardResponseBody = aNetworkEvent.discardResponseBody;
+    this._private = aNetworkEvent.private;
+  },
+
   /**
    * The "getRequestHeaders" packet type handler.
    *
@@ -1545,4 +1628,3 @@ NetworkEventActor.prototype.requestTypes =
 DebuggerServer.addTabActor(WebConsoleActor, "consoleActor");
 DebuggerServer.addGlobalActor(WebConsoleActor, "consoleActor");
 
-
diff --git a/toolkit/devtools/webconsole/WebConsoleClient.jsm b/toolkit/devtools/webconsole/WebConsoleClient.jsm
index 9c7ced146bc..8f87661e227 100644
--- a/toolkit/devtools/webconsole/WebConsoleClient.jsm
+++ b/toolkit/devtools/webconsole/WebConsoleClient.jsm
@@ -284,6 +284,23 @@ WebConsoleClient.prototype = {
     this._client.request(packet, aOnResponse);
   },
 
+  /**
+   * Send a HTTP request with the given data.
+   *
+   * @param string aData
+   *        The details of the HTTP request.
+   * @param function aOnResponse
+   *        The function invoked when the response is received.
+   */
+  sendHTTPRequest: function WCC_sendHTTPRequest(aData, aOnResponse) {
+    let packet = {
+      to: this._actor,
+      type: "sendHTTPRequest",
+      request: aData
+    };
+    this._client.request(packet, aOnResponse);
+  },
+
   /**
    * Start the given Web Console listeners.
    *
diff --git a/toolkit/devtools/webconsole/WebConsoleUtils.jsm b/toolkit/devtools/webconsole/WebConsoleUtils.jsm
index 3d8d8e553bb..3f560a0572d 100644
--- a/toolkit/devtools/webconsole/WebConsoleUtils.jsm
+++ b/toolkit/devtools/webconsole/WebConsoleUtils.jsm
@@ -1748,10 +1748,10 @@ NetworkResponseListener.prototype = {
  *        window is given, all browser network requests are logged.
  * @param object aOwner
  *        The network monitor owner. This object needs to hold:
- *        - onNetworkEvent(aRequestInfo). This method is invoked once for every
- *        new network request and it is given one arguments: the initial network
- *        request information. onNetworkEvent() must return an object which
- *        holds several add*() methods which are used to add further network
+ *        - onNetworkEvent(aRequestInfo, aChannel). This method is invoked once for
+ *        every new network request and it is given two arguments: the initial network
+ *        request information, and the channel. onNetworkEvent() must return an object
+ *        which holds several add*() methods which are used to add further network
  *        request/response information.
  *        - saveRequestAndResponseBodies property which tells if you want to log
  *        request and response bodies.
@@ -2052,7 +2052,7 @@ NetworkMonitor.prototype = {
       cookies = NetworkHelper.parseCookieHeader(cookieHeader);
     }
 
-    httpActivity.owner = this.owner.onNetworkEvent(event);
+    httpActivity.owner = this.owner.onNetworkEvent(event, aChannel);
 
     this._setupResponseListener(httpActivity);