Open Tab Highlighter

A Firefox extension that highlights links if they're already open in another browser tab.

Inspired by the painful experience of browsing job postings on sites that scroll to the top of the page when you load more entries.

Enabled on whitelisted sites by default, can be changed to all/whitelist/blacklist.

Adds an entry to right-click context menu to whitelist/blacklist/de-list current site.

Setup

Personally I use Zen and Windows, if you're on a different OS/browser your build/installation steps may vary.

1. Install dependencies, compile TS into /dist, package the addon into an .xpi file.

npm install
npm run build
npm run package

2. Open about:config in Zen
3. Set xpinstall.signatures.required to false. The file is not signed and Zen will not let you install it otherwise
4. Open about:addons
5. Click the cogwheel icon > Install add-on from file
6. Select the open-tab-highlighter.xpi file inside the dist/ folder