Compare software

HarperProWritingAid
Free

Free and open source.

 Freemium

Free to start, with a paid version that unlocks the full toolkit.

macOS, Web, Browser extension, Command line Web, Browser extension
  • All checks run locally with no telemetry
  • Works in browsers, editors and system-wide on macOS
  • Style and line-editing feedback beyond basic grammar
  • Story planning and critique tools for fiction
  • English only
  • Rule-based checks do not rewrite text the way AI assistants do
  • Full feature set requires a paid plan
  • Geared toward fiction, less so toward other writing
Downloadable app, Web application, Browser extension Downloadable app, Web application, Browser extension
Open source Closed source
License not stated License not stated
Not stated if an account is needed Account needed
Works offline Not stated if it works offline

Checked September 26, 2026

Checked September 23, 2026

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