Installing

From extension stores

Scratch Addons is available in these stores.

Chrome Web Store Firefox Add-ons

Store Install Supported browsers System requirements
Chrome Web Store Install for Chrome Web Store Google Chrome 96+
Microsoft Edge 96+
Opera 82+
Brave 1.33+
Vivaldi 5.0+
Chromium 96+		 Windows 7+
OS X / MacOS 10.11+
Add-ons for Firefox Install for Add-ons for Firefox Mozilla Firefox 109+ Windows 7+
OS X / MacOS 10.12+
Microsoft Edge Add-ons Install for Microsoft Edge Addons Microsoft Edge 96+ Windows 7+
OS X / MacOS 10.11+

From source

Unlike the store releases, installing from source requires a browser based on Chromium 121+ or Firefox 121+.

About GitHub releases

The releases page contains the code and installation files for all development builds of Scratch Addons, as well as the mirror of the store builds.

Cloning the repository

This is the recommended way to install Scratch Addons for development purposes, assuming you have Git installed.

If you plan on contributing, fork the repository on GitHub first and then clone the fork, replacing <username> with your Github username.

$ git clone https://github.com/<username>/ScratchAddons.git

To update Scratch Addons, first cd into its folder, and then run the following commands.

$ git fetch
$ git pull

Remember to also update Scratch Addons from the browser.

Downloading the Zip

This method is not recommended for development unless Git cannot be installed on the system since it will need to be manually repeated every time you update Scratch Addons.

If you do not have Git installed, use this method instead.

  1. Go to the repository and find the download code button.

  2. Click it and select “Download ZIP”.

  3. Extract the archive into a folder.

Installing on Google Chrome or Microsoft Edge

To load the extension into Google Chrome and most Chromium-based browsers such as Microsoft Edge, Opera, Brave or Vivaldi:

  1. Go to chrome://extensions

  2. Turn on “Developer mode” in the top-right corner

  3. Click “Load unpacked” and select the ScratchAddons folder.

To update the extension when testing, click the refresh icon on the extension’s card.

The “Unrecognized manifest key” warnings may safely be ignored, since they are required by Firefox.

Installing on Mozilla Firefox

To load the extension into Mozilla Firefox:

Extensions loaded into Firefox this way are temporary and must be reloaded every time the browser is restarted. Because of this Chrome is recommended for development, but everything is still expected to work on Firefox.

  1. Type about:debugging into the address bar.

  2. Click “This Firefox” on the sidebar

  3. Click “Load Temporary Add-on…”

  4. Select the manifest.json file in the ScratchAddons folder.

To reload the extension when testing, click the “Reload” button on the extension’s card.

The unexpected WebExtension manifest property warnings may safely be ignored, since they are required by Chrome.

Installing on Firefox for Android

This is only recommended if there is a mobile specific issue that cannot be easily replicated with the browser’s developer tools since extensions loaded this way are temporary and must be reinstalled over USB every time the app is restarted.

One time setup

Desktop
  1. Download and extract the Android SDK Platform Tools (Windows, MacOS, Linux).
  2. Add the folder to the PATH environment variable.
  3. Install web-ext with NPM by running npm install --global web-ext.
Android
  1. In the Android settings app, open the about page and tap the build number 7 times.
  2. Navigate to the “Developer options” page and enable “USB debugging”.
  3. Install the standard Firefox app from the Google Play store.
  4. Open the Firefox app and enable “Remote debugging via USB” in its settings.

Loading the extension

  1. Plug in the Android device and tap allow on it.
  2. Navigate to the ScratchAddons folder.
  3. Run adb devices to get the device’s serial number and ensure ADB is working.
  4. Run the following command replacing [serial number] with the one from adb devices:
web-ext run -t firefox-android --adb-device [serial number] --firefox-apk org.mozilla.firefox

The extension should install and automatically reload when changes are made, otherwise close the Firefox app and re-run the command.

Inspecting

Desktop Firefox can inspect extensions and active tabs running in the Firefox app over USB:

  1. On desktop Firefox type about:debugging into the address bar.
  2. Click “Enable USB Devices”.
  3. Click connect on the device in the sidebar. If none appear, restart desktop Firefox.
  4. Click on the device again.

Improve this page.

Comments

Make sure to follow the code of conduct. You can see this comment section on GitHub Discussions, as well as editing and removing your comment.