# Add Custom Build to Firefox * Create a local build of MetaMask using your preferred method. * You can find build instructions in the [readme](https://github.com/MetaMask/metamask-extension#readme). * Go to the url `about:debugging#addons`. * Click the button `Load Temporary Add-On`. * Select the file `metamask-extension/dist/firefox/manifest.json`. * You can optionally enable debugging, and click `Debug`, for a console window that logs all of Metamask's processes to a single console. If you have problems debugging, try connecting to the IRC channel `#webextensions` on `irc.mozilla.org`. For longer questions, use the StackOverflow tag `firefox-addons`.