Web browsers are an integral part of everyone’s internet experience. Mozilla’s Firefox is a leader in the web browsing community. With an international community of developers, Firefox is one of the world’s largest open source projects.

Firefox users can change Firefox’s default look and feel using about:preferences, which enables users to change anything from the default font to the default search engine.

Our improvements to Firefox’s about:preferences give Firefox’s 450 million users an enhanced customization experience on macOS, Windows and Linux.

Firefox users must navigate a series of tabs and pages in about:preferences to find a particular preference they wish to change. With design specifications from the User Experience team at Mozilla, these tabs and pages are now organized to make it easier for a user to find particular preferences.

Even with the improved organization, finding a particular preference among so many can still be a challenge. To this end, our improvements include a new search functionality with which users can find preferences easily and quickly.

We use Mozilla telemetry probes within Firefox to measure the impact of each of our improvements to about:preferences to determine their effectiveness.

Our code is written in JavaScript, CSS and XUL. XUL is the user interface markup language that Mozilla uses to develop Firefox.