I got a banner warning today linking to this page. It was announced a while back, but I either didn’t see it or forgot.

We have made the difficult decision to limit the use of LanguageTool’s browser extension to Premium users only. The rise of generative AI has made it more challenging to sustainably monetize our offering. A majority of users use our products for free, and the relatively small percentage of Premium subscribers is all that is subsidizing our continuously increasing server costs. To improve our Premium experience and to sustain our business model, we’ll be making the LanguageTool browser extension available exclusively for paying customers.

The key bit for people who can selfhost:

Yes. If you are a developer, you can still host and run your own instance of LanguageTool’s server. The browser extension will continue to work as it currently does for users who use it with their own server.