Extension Manifest Converter

Extension Manifest Converter is an open source tool that helps convert existing Chrome extensions to Manifest V3. Use it to convert:

• an entire unpacked directory
• an extension zip file
• just a manifest.json file.

After using the tool, complete the conversion using instructions in the Migrate to Manifest V3 guide. This tool makes the conversions listed below. To make completion of the upgrading easier, the titles and bullets below roughly correspond to the wording of the headings and items in the migration guide's checklist.

Updates to the manifest

• Changes the manifest version number.
• Updates the host permissions.

Updates that migrate to a service worker

• Upgrades the "background" field in the manifest.

Updates to API calls

• Replaces tabs.executeScript() with scripting.executeScript(). (If necessary, also adds scripting to the permissions array in the manifest.json.)
• Replaces tabs.insertCSS() with scripting.insertCSS(). You will still need to [replace tabs.removeCSS() with scripting.removeCSS()](https://developer.chrome.com/docs/extensions/migrating/api-calls/#replace-insertcss-removecss). (If necessary, also adds scripting to the permissions array in manifest.json.)
• Replaces Browser Actions and Page Actions with Actions and makes related changes to the manifest.

Improvement to extension security

• Updates the content security policy.

Limitations

This tool aims to simplify the MV3 conversion; it does not fully automate the process. Only search and replace changes are applied to .js files.

This tool does not:

• update any service worker code that relies on the DOM.

Installation

To use this tool, follow the steps below.

1. Make sure Python 3 is installed.

   python3 --version

   If you don't see a version number, follow your OS's guidance to install Python 3 or visit https://www.python.org/downloads/ to download a recent release.

2. Clone this repo using the below command.

   git clone https://github.com/GoogleChromeLabs/extension-manifest-converter

3. cd into the cloned project directory.

4. Execute the test command.

   python3 emc.py

   The tool logs basic usage information to the console.

Usage

• Convert a directory

  python3 emc.py dir/path/

• Convert a manifest file

  python3 emc.py manifest.json

• Convert a .zip file

  python3 emc.py extension.zip

License

Apache 2.0

This is not an official Google product.