Pascal Chevrel: Spell-checking for more Firefox users — a community effort

A while back, I stumbled onto something that turned into a rewarding side-project at Mozilla.

Firefox ships with a built-in spellchecker, but it only activates if a dictionary for your language is bundled with the browser. Coverage had grown organically over the years — driven largely by localizers and community members adding support for their own languages. Dictionary work was actually very active in the early years of the Mozilla project, but like many things in a large open-source codebase with a lot to manage, it had quietly received less attention over time, for no particularly good reason. So I decided to change that.

Taking stock

I put together a full and updated it with modern vocabulary, better circumflex support, and performance improvements — the result is , released under MPL-2.0. It's currently available as a is public. If you're a localizer, a linguist, or a dictionary maintainer and you want to help bring spellchecking to more Firefox users, the gaps are clearly documented. And if you maintain a dictionary that could be included but licensing is an obstacle, that's a conversation worth having.

See you in May 2027 for the next update.