diff --git a/pkg/pcloud/pcloud.go b/pkg/pcloud/pcloud.go
index 1026eab1..9c26a18d 100644
--- a/pkg/pcloud/pcloud.go
+++ b/pkg/pcloud/pcloud.go
@@ -24,7 +24,7 @@ import (
 const PCloudEndpoint = "https://api.getprompt.dev/central"
 const PCloudEndpointVarName = "PCLOUD_ENDPOINT"
 const APIVersion = 1
-const MaxPtyUpdateSize = (128 * 1024) + 1
+const MaxPtyUpdateSize = (128 * 1024)
 const MaxUpdatesPerReq = 10
 const MaxUpdateWriterErrors = 3
 const PCloudDefaultTimeout = 5 * time.Second
@@ -291,11 +291,19 @@ func makeWebShareUpdate(ctx context.Context, update *sstore.ScreenUpdateType) (*
 		if err != nil {
 			return nil, fmt.Errorf("error getting ptypos: %v", err)
 		}
-		realOffset, data, err := sstore.ReadPtyOutFile(ctx, update.ScreenId, cmdId, ptyPos, MaxPtyUpdateSize)
+		sstore.SetWebScreenPtyPosDelIntent(update.ScreenId, update.LineId)
+		realOffset, data, err := sstore.ReadPtyOutFile(ctx, update.ScreenId, cmdId, ptyPos, MaxPtyUpdateSize+1)
 		if err != nil {
 			return nil, fmt.Errorf("error getting ptydata: %v", err)
 		}
-		rtn.PtyData = &WebSharePtyData{PtyPos: realOffset, Data: data}
+		if len(data) == 0 {
+			return nil, nil
+		}
+		if len(data) > MaxPtyUpdateSize {
+			rtn.PtyData = &WebSharePtyData{PtyPos: realOffset, Data: data[0:MaxPtyUpdateSize], Eof: false}
+		} else {
+			rtn.PtyData = &WebSharePtyData{PtyPos: realOffset, Data: data, Eof: true}
+		}
 
 	default:
 		return nil, fmt.Errorf("unsupported update type (pcloud/makeWebScreenUpdate): %s\n", update.UpdateType)
@@ -306,7 +314,7 @@ func makeWebShareUpdate(ctx context.Context, update *sstore.ScreenUpdateType) (*
 func finalizeWebScreenUpdate(ctx context.Context, webUpdate *WebShareUpdateType) error {
 	switch webUpdate.UpdateType {
 	case sstore.UpdateType_PtyPos:
-		dataEof := len(webUpdate.PtyData.Data) < MaxPtyUpdateSize
+		dataEof := webUpdate.PtyData.Eof
 		newPos := webUpdate.PtyData.PtyPos + int64(len(webUpdate.PtyData.Data))
 		if dataEof {
 			err := sstore.RemoveScreenUpdate(ctx, webUpdate.UpdateId)
@@ -318,6 +326,10 @@ func finalizeWebScreenUpdate(ctx context.Context, webUpdate *WebShareUpdateType)
 		if err != nil {
 			return err
 		}
+		err = sstore.MaybeRemovePtyPosUpdate(ctx, webUpdate.ScreenId, webUpdate.LineId, webUpdate.UpdateId)
+		if err != nil {
+			return err
+		}
 
 	default:
 		err := sstore.RemoveScreenUpdate(ctx, webUpdate.UpdateId)
@@ -338,21 +350,27 @@ func DoWebScreenUpdates(authInfo AuthInfo, updateArr []*sstore.ScreenUpdateType)
 	var webUpdates []*WebShareUpdateType
 	for _, update := range updateArr {
 		webUpdate, err := makeWebShareUpdate(context.Background(), update)
-		if err != nil {
-			// log error, remove update, and continue
-			log.Printf("[pcloud] error create web-share update updateid:%d: %v", update.UpdateId, err)
-			err = sstore.RemoveScreenUpdate(context.Background(), update.UpdateId)
+		if err != nil || webUpdate == nil {
+			// log error (if there is one), remove update, and continue
+			if err != nil {
+				log.Printf("[pcloud] error create web-share update updateid:%d: %v", update.UpdateId, err)
+			}
+			if update.UpdateType == sstore.UpdateType_PtyPos {
+				err = sstore.MaybeRemovePtyPosUpdate(context.Background(), update.ScreenId, update.LineId, update.UpdateId)
+			} else {
+				err = sstore.RemoveScreenUpdate(context.Background(), update.UpdateId)
+			}
 			if err != nil {
 				// ignore this error too (although this is really problematic, there is nothing to do)
 				log.Printf("[pcloud] error removing screen update updateid:%d: %v", update.UpdateId, err)
 			}
 			continue
 		}
-		if webUpdate == nil {
-			continue
-		}
 		webUpdates = append(webUpdates, webUpdate)
 	}
+	if len(webUpdates) == 0 {
+		return nil
+	}
 	ctx, cancelFn := context.WithTimeout(context.Background(), PCloudDefaultTimeout)
 	defer cancelFn()
 	req, err := makeAuthPostReq(ctx, WebShareUpdateUrl, authInfo, webUpdates)
diff --git a/pkg/pcloud/pclouddata.go b/pkg/pcloud/pclouddata.go
index 7f56edee..102fe76d 100644
--- a/pkg/pcloud/pclouddata.go
+++ b/pkg/pcloud/pclouddata.go
@@ -156,4 +156,5 @@ func webCmdFromCmd(lineId string, cmd *sstore.CmdType) (*WebShareCmdType, error)
 type WebSharePtyData struct {
 	PtyPos int64  `json:"ptypos,omitempty"`
 	Data   []byte `json:"data,omitempty"`
+	Eof    bool   `json:"-"` // internal use
 }
diff --git a/pkg/sstore/dbops.go b/pkg/sstore/dbops.go
index 647dc282..f6fd32a5 100644
--- a/pkg/sstore/dbops.go
+++ b/pkg/sstore/dbops.go
@@ -24,6 +24,8 @@ const DefaultMaxHistoryItems = 1000
 
 var updateWriterCVar = sync.NewCond(&sync.Mutex{})
 var updateWriterMoreData = false
+var WebScreenPtyPosLock = &sync.Mutex{}
+var WebScreenPtyPosDelIntent = make(map[string]bool) // map[screenid + ":" + lineid] -> bool
 
 type SingleConnDBGetter struct {
 	SingleConnLock *sync.Mutex
@@ -2400,12 +2402,16 @@ func ScreenWebShareStart(ctx context.Context, screenId string, shareOpts ScreenW
 		if shareMode != ShareModeLocal {
 			return fmt.Errorf("screen cannot be shared, invalid current share mode %q (must be local)", shareMode)
 		}
+		nowTs := time.Now().UnixMilli()
 		query = `UPDATE screen SET sharemode = ?, webshareopts = ? WHERE screenid = ?`
 		tx.Exec(query, ShareModeWeb, quickJson(shareOpts), screenId)
 		insertScreenUpdate(tx, screenId, UpdateType_ScreenNew)
 		query = `INSERT INTO screenupdate (screenid, lineid, updatetype, updatets)
                  SELECT screenid, lineid, ?, ? FROM line WHERE screenid = ? ORDER BY linenum`
-		tx.Exec(query, UpdateType_LineNew, time.Now().UnixMilli(), screenId)
+		tx.Exec(query, UpdateType_LineNew, nowTs, screenId)
+		query = `INSERT INTO screenupdate (screenid, lineid, updatetype, updatets)
+                 SELECT c.screenid, l.lineid, ?, ? FROM cmd c, line l WHERE c.screenid = ? AND l.cmdid = c.cmdid`
+		tx.Exec(query, UpdateType_PtyPos, nowTs, screenId)
 		NotifyUpdateWriter()
 		return nil
 	})
@@ -2425,6 +2431,8 @@ func ScreenWebShareStop(ctx context.Context, screenId string) error {
 		tx.Exec(query, ShareModeLocal, "null", screenId)
 		query = `DELETE FROM screenupdate WHERE screenid = ?`
 		tx.Exec(query, screenId)
+		query = `DELETE FROM webptypos WHERE screenid = ?`
+		tx.Exec(query, screenId)
 		insertScreenUpdate(tx, screenId, UpdateType_ScreenDel)
 		return nil
 	})
@@ -2494,13 +2502,31 @@ func RemoveScreenUpdate(ctx context.Context, updateId int64) error {
 	})
 }
 
-func InsertPtyPosUpdate(ctx context.Context, screenId string, cmdId string) error {
+func SetWebScreenPtyPosDelIntent(screenId string, lineId string) {
+	WebScreenPtyPosLock.Lock()
+	defer WebScreenPtyPosLock.Unlock()
+	WebScreenPtyPosDelIntent[screenId+":"+lineId] = true
+}
+
+func ClearWebScreenPtyPosDelIntent(screenId string, lineId string) bool {
+	WebScreenPtyPosLock.Lock()
+	defer WebScreenPtyPosLock.Unlock()
+	rtn := WebScreenPtyPosDelIntent[screenId+":"+lineId]
+	delete(WebScreenPtyPosDelIntent, screenId+":"+lineId)
+	return rtn
+}
+
+func MaybeInsertPtyPosUpdate(ctx context.Context, screenId string, cmdId string) error {
 	return WithTx(ctx, func(tx *TxWrap) error {
+		if !isWebShare(tx, screenId) {
+			return nil
+		}
 		query := `SELECT lineid FROM line WHERE screenid = ? AND cmdid = ?`
 		lineId := tx.GetString(query, screenId, cmdId)
 		if lineId == "" {
 			return fmt.Errorf("invalid ptypos update, no lineid found for %s/%s", screenId, cmdId)
 		}
+		ClearWebScreenPtyPosDelIntent(screenId, lineId) // clear delete intention because we have a new update
 		query = `SELECT updateid FROM screenupdate WHERE screenid = ? AND lineid = ? AND updatetype = ?`
 		if !tx.Exists(query, screenId, lineId, UpdateType_PtyPos) {
 			query := `INSERT INTO screenupdate (screenid, lineid, updatetype, updatets) VALUES (?, ?, ?, ?)`
@@ -2511,6 +2537,18 @@ func InsertPtyPosUpdate(ctx context.Context, screenId string, cmdId string) erro
 	})
 }
 
+func MaybeRemovePtyPosUpdate(ctx context.Context, screenId string, lineId string, updateId int64) error {
+	return WithTx(ctx, func(tx *TxWrap) error {
+		intent := ClearWebScreenPtyPosDelIntent(screenId, lineId) // check for intention before deleting
+		if !intent {
+			return nil
+		}
+		query := `DELETE FROM screenupdate WHERE updateid = ?`
+		tx.Exec(query, updateId)
+		return nil
+	})
+}
+
 func GetWebPtyPos(ctx context.Context, screenId string, lineId string) (int64, error) {
 	return WithTxRtn(ctx, func(tx *TxWrap) (int64, error) {
 		query := `SELECT ptypos FROM webptypos WHERE screenid = ? AND lineid = ?`
diff --git a/pkg/sstore/fileops.go b/pkg/sstore/fileops.go
index 9361f445..c2f8e050 100644
--- a/pkg/sstore/fileops.go
+++ b/pkg/sstore/fileops.go
@@ -61,7 +61,7 @@ func AppendToCmdPtyBlob(ctx context.Context, screenId string, cmdId string, data
 		PtyData64:  data64,
 		PtyDataLen: int64(len(data)),
 	}
-	err = InsertPtyPosUpdate(ctx, screenId, cmdId)
+	err = MaybeInsertPtyPosUpdate(ctx, screenId, cmdId)
 	if err != nil {
 		// just log
 		log.Printf("error inserting ptypos update %s/%s: %v\n", screenId, cmdId, err)