Install Stylus from GitHub

This article describes the installation of Stylus for testing purpose. See releases on the main page for permanent installation.
BACK UP YOUR STYLES before you begin or you may lose them.

Contents:

• Download and Extract the Extension.
• Install in Chrome.
• Install in Firefox.
  • Temporary installation.
  • Semi-permanent installation.

To test an unreleased update to our extension, you'll need to take a few extra steps to load it into the browser:

Download and Extract the Extension

• Select the branch (1-2); make sure the clicked button (1) shows "Branch:" followed by the branch name to test.

  

• Click the "Clone or download" button (1) and then click "Download ZIP" (2).

  

• Extract the ZIP folder in an easy to find location, like the desktop.

  • Extracting a ZIP file is built-in to newer versions of Windows & Mac OS.
  • For older versions, search Google for "unzip" . And install the necessary software.

Install in Chrome

• Open the following URL: chrome://extensions/.

• Check the "Developer mode" checkbox at the top (1).

• Click "Load unpacked extension..." (2).

  

• Select the extracted "stylus" folder (3) and click "OK" (4).

  

• Don't forget to disable any other versions of Stylus that are already installed!

Install in Firefox

Temporary Firefox installation

• Open the following URL: about:debugging#addons

• Click the "Load Temporary Add-on" button (1).

• Select the extracted "stylus" folder (2).

• Select any file within the folder (3). Any file will work.

• Click "Open" (4).

  

• Don't forget to disable any other versions of Stylus that are already installed!

• Also see Mozilla's video .

Semi-permanent Firefox installation

To install Stylus in Firefox without needing to follow the above steps every time you load Firefox:

• This won't work with the standard version of Firefox. It has been known to work on Developer Edition, Nightly , and LibreWolf . If you try another edition or fork, please edit this page to mention it.

• Now zip up all of the contents of the stylus folder. Don't zip the folder itself; instead go into the folder, select everything, and zip all of it.

• Go to the Firefox about:addons page.

• Click the gear icon at the top of the page, and choose "Install Add-on From File..."

  

• Select the zip file you just made, and click "Open."

• If you get a message saying that the add-on could not be installed because it appears to be corrupt, then you've made a mistake in downloading, unzipping, and rezipping the extension. Again: the zip file should contain a bunch of files and folders; it should not contain a folder that contains those files and folders.

• If you get a message saying that the add-on could not be installed because it's not verified, then go to about:config, search for xpinstall.signatures.required, and set it to false. Then try installing from file again. If you get the same error message, then you're out of luck for that edition of Firefox.