diff --git a/src/CharWidth.api.ts b/src/CharWidth.api.ts
new file mode 100644
index 00000000..baa8600c
--- /dev/null
+++ b/src/CharWidth.api.ts
@@ -0,0 +1,114 @@
+/**
+ * Copyright (c) 2017 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import * as puppeteer from 'puppeteer';
+import { assert } from 'chai';
+// import { getStringCellWidth } from './CharWidth';
+import { ITerminalOptions } from 'xterm';
+
+const APP = 'http://127.0.0.1:3000/test';
+
+let browser: puppeteer.Browser;
+let page: puppeteer.Page;
+const width = 800;
+const height = 600;
+
+describe('CharWidth Integration Tests', function(): void {
+  this.timeout(20000);
+
+  before(async function(): Promise<any> {
+    browser = await puppeteer.launch({
+      headless: process.argv.indexOf('--headless') !== -1,
+      slowMo: 80,
+      args: [`--window-size=${width},${height}`]
+    });
+    page = (await browser.pages())[0];
+    await page.setViewport({ width, height });
+    await page.goto(APP);
+    await openTerminal({ rows: 5, cols: 30 });
+  });
+
+  after(() => {
+    browser.close();
+  });
+
+  describe('getStringCellWidth', () => {
+    beforeEach(async () => {
+      await page.evaluate(`window.term.reset()`);
+    });
+
+    it('ASCII chars', async function(): Promise<void> {
+      const input = 'This is just ASCII text.#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(25, await sumWidths(0, 1, '#'));
+    });
+
+    it('combining chars', async function(): Promise<void> {
+      const input = 'e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(10, await sumWidths(0, 1, '#'));
+    });
+
+    it('surrogate chars', async function(): Promise<void> {
+      const input = '𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(28, await sumWidths(0, 1, '#'));
+    });
+
+    it('surrogate combining chars', async function(): Promise<void> {
+      const input = '𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(12, await sumWidths(0, 1, '#'));
+    });
+
+    it('fullwidth chars', async function(): Promise<void> {
+      const input = '１２３４５６７８９０#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(21, await sumWidths(0, 1, '#'));
+    });
+
+    it('fullwidth chars offset 1', async function(): Promise<void> {
+      const input = 'a１２３４５６７８９０#';
+      await page.evaluate(`window.term.write('${input}')`);
+      assert.equal(22, await sumWidths(0, 1, '#'));
+    });
+
+    // TODO: multiline tests once #1685 is resolved
+  });
+});
+
+async function openTerminal(options: ITerminalOptions = {}): Promise<void> {
+  await page.evaluate(`window.term = new Terminal(${JSON.stringify(options)})`);
+  await page.evaluate(`window.term.open(document.querySelector('#terminal-container'))`);
+  if (options.rendererType === 'dom') {
+    await page.waitForSelector('.xterm-rows');
+  } else {
+    await page.waitForSelector('.xterm-text-layer');
+  }
+}
+
+async function sumWidths(start: number, end: number, sentinel: string): Promise<number> {
+  await page.evaluate(`
+    (function() {
+      window.result = 0;
+      const buffer = window.term.buffer;
+      for (let i = ${start}; i < ${end}; i++) {
+        const line = buffer.getLine(i);
+        let j = 0;
+        while (true) {
+          const cell = line.getCell(j++);
+          if (!cell) {
+            break;
+          }
+          window.result += cell.width;
+          if (cell.char === '${sentinel}') {
+            return;
+          }
+        }
+      }
+    })();
+  `);
+  return await page.evaluate(`window.result`);
+}
diff --git a/src/CharWidth.test.ts b/src/CharWidth.test.ts
index 4aec3995..9b5a75af 100644
--- a/src/CharWidth.test.ts
+++ b/src/CharWidth.test.ts
@@ -3,80 +3,8 @@
  * @license MIT
  */
 
-import { TestTerminal } from './TestUtils.test';
 import { assert } from 'chai';
-import { getStringCellWidth, wcwidth } from './CharWidth';
-import { IBuffer } from './Types';
-import { CellData, CHAR_DATA_WIDTH_INDEX, CHAR_DATA_CHAR_INDEX } from 'core/buffer/BufferLine';
-
-
-describe('getStringCellWidth', function(): void {
-  let terminal: TestTerminal;
-
-  beforeEach(() => {
-    terminal = new TestTerminal({rows: 5, cols: 30});
-  });
-
-  function sumWidths(buffer: IBuffer, start: number, end: number, sentinel: string): number {
-    let result = 0;
-    for (let i = start; i < end; ++i) {
-      const line = buffer.lines.get(i);
-      for (let j = 0; j < line.length; ++j) { // TODO: change to trimBorder with multiline
-        const ch = line.loadCell(j, new CellData()).getAsCharData();
-        result += ch[CHAR_DATA_WIDTH_INDEX];
-        // return on sentinel
-        if (ch[CHAR_DATA_CHAR_INDEX] === sentinel) {
-          return result;
-        }
-      }
-    }
-    return result;
-  }
-
-  it('ASCII chars', function(): void {
-    const input = 'This is just ASCII text.#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  it('combining chars', function(): void {
-    const input = 'e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301e\u0301#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  it('surrogate chars', function(): void {
-    const input = '𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞𝄞#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  it('surrogate combining chars', function(): void {
-    const input = '𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301𓂀\u0301#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  it('fullwidth chars', function(): void {
-    const input = '１２３４５６７８９０#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  it('fullwidth chars offset 1', function(): void {
-    const input = 'a１２３４５６７８９０#';
-    terminal.writeSync(input);
-    const s = terminal.buffer.iterator(true).next().content;
-    assert.equal(input, s);
-    assert.equal(getStringCellWidth(s), sumWidths(terminal.buffer, 0, 1, '#'));
-  });
-  // TODO: multiline tests once #1685 is resolved
-});
+import { wcwidth } from './CharWidth';
 
 it('wcwidth should match all values from the old implementation', function(): void {
   // old implementation