Universal Language Selector/New ULS

We are modernizing the main content language selector, the interface that lets readers and editors switch between language versions of a Wikipedia page.

The Universal Language Selector (ULS) has been part of MediaWiki since 2013. Over time, the underlying technology became difficult to maintain and update. Long-standing issues with accessibility, performance, and visual consistency could not be fixed without rebuilding the component from the ground up.

Rather than rewriting every part of ULS at once, we rescoped the project to focus on the most visible and most-used part: the content language selector. This keeps the work focused and deliverable while addressing the issues that affect the most people.

The updated selector is built with Codex, the Wikimedia design system, and modern web standards. Key improvements include:

• Faster and more reliable: the selector opens and responds faster, with fewer layout shifts and unexpected behaviors
• Dark mode support: the selector now displays correctly for users who have dark mode enabled
• Improved keyboard and screen reader navigation: the selector meets current accessibility standards, addressing long-standing issues with keyboard navigation and how content was represented to assistive technologies
• Language pinning: users can now pin their preferred languages for quicker access, making it faster to switch between the languages they use most often
• More consistent across surfaces: visual and behavioral inconsistencies between different places where the selector appeared have been reduced

The selector's overall behavior remains close to what users are already familiar with.

This modernization is focused on the content language selector. Other parts of ULS, including web fonts and input methods, are not part of this work and continue to function as before.

The work is nearly complete. The updated selector is being deployed gradually in the upcoming weeks, starting with pilot wikis, before rolling out more broadly. A Beta feature is available for early testing and feedback.

If you encounter unexpected behavior or have feedback on the updated selector, please leave a note on the talk page or file a task in Phabricator.

• Preferred languages are currently not being saved as global preferences. This is being looked at on priority.
• After selecting preferred languages in the settings dialog, a refresh is needed to display the updated preferred language list in the new ULS.