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Harper vs Grammarly for Microsoft Edge: catalog facts
Harper	Grammarly for Microsoft Edge
Free Free and open source.	Freemium The extension is free to install, with paid Grammarly plans for more features.
macOS, Web, Browser extension, Command line	Browser extension
All checks run locally with no telemetry Works in browsers, editors and system-wide on macOS	Checks grammar and spelling directly in web pages AI suggestions for rewriting and drafting text
English only Rule-based checks do not rewrite text the way AI assistants do	Text is processed by Grammarly's online service Only covers writing done inside the browser
Downloadable app, Web application, Browser extension	Browser extension
Open source	Closed source
License not stated	License not stated
Not stated if an account is needed	Not stated if an account is needed
Works offline	Not stated if it works offline
Official website Full listing and sources Checked September 26, 2026	Official website Full listing and sources Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.