Some settings for Firefox cannot be adjusted in the normal way (via the “Settings” menu item).
Remove service workers
Open about:debugging#/runtime/this-firefox in the address bar.
Delete all listed service workers by enteringfor (let button of document.querySelectorAll(".qa-unregister-button")) { button.click(); }
in the debugger console.
More than 4 rows of top sites on start page
Open about:config in the address bar.
Enter browser.newtabpage.activity-stream.topSitesRows in the search field.
Enter the desired number of rows.
Keep backspace key from going back to previous page
Open about:config in the address bar.
Enter browser.backspace_action in the search field.
Set the value to 2 to unmap the backspace key.
Customise/hide elements on websites
Open about:config in the address bar.
Enter toolkit.legacyUserProfileCustomizations.stylesheets in the search field.
Set the value to true to activate the custom css.
Open the user folder:
Linux: /home/[user name]/.mozilla/firefox/[profile-id].default-release/
MacOS: /Users/[user name]/Library/Application Support/Firefox/Profiles/[profile-id].default-release/
Create a subfolder “chrome” (if it doesn’t already exist) and create a file “userContent.css” in it.
In this file, define styles for elements on defined domains, e.g.@-moz-document domain(www.ex-parrot.de) {
.sample-class {
display: none !important;
}
#sample-id {
font-weight: bold !important;
}
}
Activate new/modified styles by restarting Firefox.
Add custom search engines (no OpenSearch Support)
Open about:config in the address bar.
Enter browser.urlbar.update2.engineAliasRefresh in the search field and set it to true.
Go to “Settings” → “Search.”
In the “Search Shortcuts” section, you should now see an “Add” button.
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