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OpenAlternative

Open Source Grammarly Alternatives

A curated collection of the 2 best open source alternatives to Grammarly.

The best open source alternative to Grammarly is LanguageTool. If that does not suit you, we have compiled a ranked list of other open source Grammarly alternatives to help you find a suitable replacement.

Grammarly alternatives are mainly Browser Extensions. Browse these if you want a narrower list of alternatives or are looking for a specific functionality of Grammarly.

Written by OpenAlternative Last updated: June 2, 2026
#1

LanguageTool

Check grammar, punctuation, and spelling errors instantly with AI-powered technology. Supports 30+ languages with browser extensions and desktop apps.

Check grammar, punctuation, and spelling errors instantly with AI-powered ...

#2

Harper

Open source grammar checker that analyzes your writing quickly while keeping your data completely private and secure on your device.

Open source grammar checker that analyzes your writing quickly while keepi...