Manifest - key

This value maintains the unique ID of an extension, or theme when it is loaded during development. The following are some common use cases:

  • To configure a server to only accept requests from your Chrome Extension origin.
  • So that other extensions or websites can send messages to your extension.
  • So that a website can access the web_accessible_resources of your extension.

Keep a consistent extension ID

Preserving a single ID is essential during development. To keep a consistent ID, follow these steps:

Upload extension to the developer dashboard

Package the extension directory into a .zip file and upload it to the Chrome Developer Dashboard without publishing it:

  1. On the Developer Dashboard, click Add new item.
  2. Click Browse files, select the extension's zip file, and upload it.
  3. Go to the Package tab and click View public key.

Developer Dashboard Package tab

When the popup is open, follow these steps:

  1. Copy the code in between -----BEGIN PUBLIC KEY----- and -----END PUBLIC KEY-----.
  2. Remove the newlines in order to make it a single line of text.

Public key popup

Add the code to the manifest.json under the "key" field. This way the extension will use the same ID.

{ // manifest.json
  "manifest_version": 3,
  "key": "ThisKeyIsGoingToBeVeryLong/go8GGC2u3UD9WI3MkmBgyiDPP2OreImEQhPvwpliioUMJmERZK3zPAx72z8MDvGp7Fx7ZlzuZpL4yyp4zXBI+MUhFGoqEh32oYnm4qkS4JpjWva5Ktn4YpAWxd4pSCVs8I4MZms20+yx5OlnlmWQEwQiiIwPPwG1e1jRw0Ak5duPpE3uysVGZXkGhC5FyOFM+oVXwc1kMqrrKnQiMJ3lgh59LjkX4z1cDNX3MomyUMJ+I+DaWC2VdHggB74BNANSd+zkPQeNKg3o7FetlDJya1bk8ofdNBARxHFMBtMXu/ONfCT3Q2kCY9gZDRktmNRiHG/1cXhkIcN1RWrbsCkwIDAQAB",

Compare IDs

Open the Extensions Management page at chrome://extensions, ensure Developer mode is enabled, and upload the unpackaged extension directory. Compare the extension ID on the extensions management page to the Item ID in the Developer Dashboard. They should match.

The ID of the
extension match