Interesting, I would love to hear how well those worked.

Grammit uses the Prompt API for the local LLM, which currently uses a version of the Gemma 3n model on Chrome.

Grammit uses prompting instead of fine-tuning or custom training. Simplified, it has a system prompt along the lines of: "Rewrite this text, correcting any grammar or spelling mistakes," combined with a prefilled conversation containing a number of examples showing an input sentence and the corrected output.