Looking to replace Grammarly? These open source alternatives give you the same core workflow without the lock-in - free to use, often self-hostable, and auditable on GitHub. Compare licenses, languages and project activity, then switch on your own terms.
LanguageTool is open-source proofreading software for English, Spanish, French, German, Portuguese, Polish, Dutch, and more than 20 other languages. It finds many errors that a simple spell checker cannot detect, covering grammar, punctuation, spelling, and style issues for multilingual writing.
Harper is an open-source English grammar and spell checker for developers and writers. It is designed to lint writing locally instead of sending text to a server, addressing privacy and latency concerns in server-based grammar tools.
Vale is a command-line tool that brings code-like linting to prose. It helps teams check documentation and other written content with repeatable rules instead of editor-specific suggestions. It runs on Windows, macOS, and Linux and is written in Go.
