Chrome, Brave, or Edge
- Open the CoBlocks Chrome Web Store listing in your desktop browser.
- Click the install button and confirm. Edge may first ask you to allow extensions from other stores.
- Refresh Scratch, open the CoBlocks popup, and sign in with Scratch Auth.
Firefox
- Download the extension package from GitHub Releases and extract it.
- Open about:debugging#/runtime/this-firefox, choose Load Temporary Add-on, and select the extracted manifest.json.
- Allow site access, refresh Scratch, and sign in through the CoBlocks popup.
Other browsers and manual installation
Opera and Vivaldi can use Chromium-style extensions, but compatibility may vary. Safari cannot install the Chrome Web Store package. Use a supported desktop browser; mobile support is not assumed.
More detail & reference
Choose a distribution
| Build | When to use it |
|---|---|
| Chrome Web Store | Convenient installation and browser-managed updates for compatible desktop Chromium browsers. Check the version on the listing and in the popup. |
| GitHub extension package | The published release package, loaded manually in Chrome, Brave, or Edge. This is also the package used for temporary Firefox installation. |
| Firefox 140+ | Load the manifest temporarily using about:debugging. A permanent install requires a Mozilla-signed package; the release package is a ZIP, not a signed store listing. |
Google Chrome
The released manifest requires Chrome 121 or newer. For a GitHub package, follow Load unpacked below.
- Open the CoBlocks Chrome Web Store listing in desktop Chrome.
- Select Add to Chrome, review the requested permissions, and confirm Add extension.
- Use the extensions menu to pin CoBlocks if you want its icon visible.
- Refresh any Scratch tabs that were already open, sign in to Scratch, and open CoBlocks to connect your account.
Brave
- Open the same Chrome Web Store listing in desktop Brave.
- Choose Add to Brave (the store may display Add to Chrome), then confirm the browser’s installation prompt.
- Pin CoBlocks through Brave’s extensions menu and reload your Scratch tab.
- Complete Scratch Auth from the CoBlocks popup.
Microsoft Edge
- Visit the Chrome Web Store listing in desktop Edge.
- If Edge asks, allow extensions from other stores. This option is also available at edge://extensions.
- Select the listing’s install button and confirm Add extension.
- Reload Scratch and sign in from the CoBlocks popup.
Load the GitHub package in Chrome, Brave, or Edge
- Download extension.zip from latest release and extract it to a folder you will keep.
- Open chrome://extensions, brave://extensions, or edge://extensions in your browser’s address bar.
- Enable Developer mode and choose Load unpacked.
- Select the extracted folder that directly contains manifest.json. If the ZIP has a nested extension folder, select that inner folder.
- Confirm CoBlocks appears without errors. Refresh Scratch and complete Scratch Auth.
Firefox 140+ — temporary installation
- Download the latest extension package and extract it.
- Open about:debugging#/runtime/this-firefox in desktop Firefox.
- Choose Load Temporary Add-on and select manifest.json inside the extracted extension folder.
- Allow access to Scratch and the CoBlocks API when prompted.
- Reload Scratch, sign in to Scratch, and finish Scratch Auth through the popup.
Vivaldi desktop — Chromium route
- Open the Chrome Web Store listing in Vivaldi and choose Add to Vivaldi.
- If that button is unavailable, check Settings → Privacy and Security → Google Extensions → Web Store.
- Alternatively, open vivaldi://extensions, enable Developer mode, and Load unpacked from the extracted folder containing manifest.json.
- Refresh Scratch, allow site access, and complete Scratch Auth.
Opera desktop — Chromium route
- Open the CoBlocks Chrome Web Store listing in Opera and use the offered install control if available.
- If your Opera build does not allow that route, extract the GitHub ZIP, open opera://extensions, enable Developer mode, and use Load unpacked with the folder containing manifest.json.
- Refresh Scratch and check CoBlocks site access before completing Scratch Auth.
Safari and mobile
| Browser | What to expect |
|---|---|
| Safari on macOS / iOS | The Chrome Web Store ZIP is not a Safari extension. No Safari build is included in the verified release. Use a supported desktop browser. |
| Mobile browsers | This wiki does not claim mobile support. A mobile browser name matching Chrome or Firefox does not establish that the desktop installation steps will work. |
Verify the installation
- The popup opens and shows its version.
- CoBlocks has permission to run on scratch.mit.edu and contact your chosen backend.
- After signing in, the popup shows the friends list instead of the connection dialog.
- On a project you own, the editor shows CoBlocks beside Share.