Microsoft Edge browser extension development

Edge Extension Development

Microsoft Edge has been running on the Chromium engine since 2020, so Chrome Extensions are compatible with Edge with practically no changes. Edge even supports installing extensions from Chrome Web Store directly. However, publishing to Microsoft Edge Add-ons (equivalent to Chrome Web Store) and corporate deployment via Active Directory are separate tasks.

Compatibility with Chrome

Edge supports identical Chrome Extensions API. The chrome.* namespace works in Edge the same way as in Chrome. The only thing to remember:

// Both work in Edge
chrome.storage.local.set({ key: 'value' });
browser.storage.local.set({ key: 'value' }); // with webextension-polyfill

An extension written for Chrome MV3 installs in Edge without changes — just upload the same ZIP.

Edge API specifics

Edge added several proprietary APIs unavailable in Chrome:

// Sync via Microsoft account
// (similar to chrome.storage.sync, but via OneDrive)
// Available via standard chrome.storage.sync in Edge

// Microsoft Graph integration — via web requests, not via special API
// Edge Collections — no public API for extensions

// Edge side panel (separate from chrome.sidePanel)
// manifest.json:
"side_panel": {
  "default_path": "panel.html"
}

Manifest.json with Edge-specific settings

{
  "manifest_version": 3,
  "name": "My Edge Extension",
  "version": "1.0.0",
  "permissions": ["storage", "tabs", "activeTab", "scripting"],
  "background": {
    "service_worker": "background.js"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon48.png"
  },
  "content_scripts": [{
    "matches": ["https://*/*"],
    "js": ["content.js"],
    "run_at": "document_idle"
  }],
  "browser_specific_settings": {
    "edge": {
      "browser_action_next_to_addressbar": true
    }
  }
}

Testing in Edge

# Load unpacked extension
# edge://extensions/ → Developer mode → Load unpacked extension

# Or via CLI (Edge must be installed)
"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" \
  --load-extension="C:\path\to\extension"

Publishing to Microsoft Edge Add-ons

1. Register Microsoft Partner Center account
2. Go to Edge Add-ons Developer Dashboard
3. Upload ZIP with extension
4. Fill in metadata (description, screenshots, category)
5. Wait for review (usually 3–7 working days)

Review is stricter than Chrome Web Store — Microsoft separately checks privacy policy.

Corporate deployment via Group Policy

Edge as a corporate browser supports extension deployment via GPO without App Store:

<!-- ExtensionInstallForcelist via ADMX/GPO -->
<!-- Value: extension-id;update-url -->
<!-- For local extension you need own update server -->
<policy name="ExtensionInstallForcelist">
  <value>abcdefghijklmnopabcdefghijklmnop;https://update.example.com/updates.xml</value>
</policy>

Update server (minimal implementation):

<!-- updates.xml -->
<?xml version='1.0' encoding='UTF-8'?>
<gupdate xmlns='http://www.google.com/update2/response' protocol='2.0'>
  <app appid='abcdefghijklmnopabcdefghijklmnop'>
    <updatecheck codebase='https://update.example.com/extension.crx'
                 version='1.0.0' />
  </app>
</gupdate>

To package .crx without Chrome Web Store:

# Via Chromium CLI
chromium --pack-extension=/path/to/extension \
         --pack-extension-key=/path/to/key.pem

Edge operation modes: IE Mode

Edge supports Internet Explorer mode for legacy sites. Extensions in IE Mode don't work — the tab switches to Trident engine. If the extension needs to work on corporate legacy sites, this limitation must be considered at the design stage.

Timeline

Adapting Chrome Extension for Edge Add-ons Store (repackaging + metadata + review) — 1–2 working days. Extension with Edge-specific functionality (side panel, corporate GPO deployment) — 3–5 days additional.