Spell checking without sending everything you type to the cloud
A grammar checker in the browser reads everything you write: mails, chat messages, internal documents, notes about customers. With most tools, all of that goes to a vendor's cloud.
For a long time, LanguageTool was the friendly exception. Its checking engine is open source (LGPL-2.1), it is still actively developed, and you can run it on your own machine. The browser add-on took a different path:
- 2019: the add-on became closed source. The team said they had to pay people to work on it.
- April 2023: Learneo, the parent company of QuillBot, bought LanguageTool. The open-source engine was promised to stay unaffected, and so far it has.
- March 2026: the browser extension became Premium-only. After a 14-day trial, it stops underlining mistakes for free users. The reason given: "The rise of generative AI has made it more challenging to sustainably monetize our offering." Free users are pointed to QuillBot.
So I built Inkling. It is an open-source (Apache-2.0) extension for Chrome and Firefox that talks only to the LanguageTool server you choose. It needs no account and has no trial. It is a fork of the browser extension of Harper by Automattic. The Harper team did the hard work of placing marks correctly in Google Docs and the common rich-text editors.
Running your own server takes one command:
podman run -d -p 8010:8010 erikvl87/languagetool
(Docker works the same way.) Then install Inkling, enter http://localhost:8010 and click "Save and Test". Your text never leaves your laptop. A team can also share one server on its internal network.
Chrome: https://chromewebstore.google.com/detail/inkling/lncfkjkgeoepkinifaggpblhpbenemej
Firefox: https://addons.mozilla.org/firefox/addon/inkling/
Source: https://github.com/oetiker/inkling
Thanks to the LanguageTool developers for keeping the engine open, and to the Harper team for the browser integration.
