Compare software

ProWritingAidHarper
Freemium

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

 Free

Free and open source.

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

Checked September 23, 2026

Checked September 26, 2026

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