Useful tricks for Firefox

Some settings for Firefox cannot be adjusted in the normal way (via the “Settings” menu item).

Remove service workers

1. Open about:debugging#/runtime/this-firefox in the address bar.
2. Delete all listed service workers by entering
   for (let button of document.querySelectorAll(".qa-unregister-button")) { button.click(); }
   in the debugger console.

More than 4 rows of top sites on start page

1. Open about:config in the address bar.
2. Enter browser.newtabpage.activity-stream.topSitesRows in the search field.
3. Enter the desired number of rows.

Keep backspace key from going back to previous page

1. Open about:config in the address bar.
2. Enter browser.backspace_action in the search field.
3. Set the value to 2 to unmap the backspace key.

Customise/hide elements on websites

Add custom search engines (no OpenSearch Support)

1. Open about:config in the address bar.
2. Enter browser.urlbar.update2.engineAliasRefresh in the search field and set it to true.
3. Go to “Settings” → “Search.”
4. In the “Search Shortcuts” section, you should now see an “Add” button.
5. Click “Add” and fill in:
• Name (e.g., “Custom Search”)
• Search URL (replace the search term with %s, e.g., https://www.example.com/search?q=%s)
• Optional keyword for quick access
6. Save your new search engine.