Grammarly vs ProWritingAid

Updated October 2026 · AppBreakup editorial

Grammarly

The best-known grammar and tone checker, with AI drafting built into a browser extension and desktop apps.

Free plan + paid

Visit Grammarly Grammarly profile

ProWritingAid

A style editor and manuscript analyser built for novelists and long-form writers.

Free plan + paid

Visit ProWritingAid ProWritingAid profile

The short answer

Grammarly suits people who want quick corrections and AI help in every app they type in, including phones. ProWritingAid suits novelists and long-form writers who want deep style reports on a whole manuscript. The biggest difference is depth versus reach: ProWritingAid offers 25+ writing reports and a lifetime licence, while Grammarly runs in more places with a cleaner interface.

Grammarly or ProWritingAid: our take

Grammarly is designed to stay out of the way. Suggestions appear inline as you type in browsers, desktop apps and on its iPhone and Android keyboards, and you accept or dismiss them one at a time. Generative AI handles drafting, rewriting and tone changes. ProWritingAid is designed for revision. Beyond grammar, it runs more than 25 reports on overused words, sentence-length variety, pacing, dialogue tags, clichés, sticky sentences and readability, plus AI rephrasing, chapter critiques and Story Canvas tools for planning plots. It works in a web editor, a browser extension, Google Docs, Microsoft Office and a desktop app, but it has no phone keyboard.

Pricing is where the two differ most. Grammarly has a free plan with 100 AI prompts a month, and Pro starts at $12 per member per month billed annually. ProWritingAid has a limited free plan, and Premium costs $10/month billed yearly or $30/month monthly, or $399 one-time for a lifetime licence, which appeals to writers who dislike subscriptions. Some of ProWritingAid's advanced AI critiques use separate credits. Grammarly adds team style guides and brand tones on business plans, which matters more to companies than to authors.

If you write emails, reports and messages all day and want errors caught wherever you are, Grammarly is the simpler choice. If you are revising a novel or a long non-fiction draft and want to study patterns in your prose, ProWritingAid gives far more detail, at the cost of a busier interface that can feel overwhelming. Both are English-focused and process text in the cloud, so neither fits work that must stay on your own machine.

Choose Grammarly if…

English writers who want corrections and AI help everywhere they type, without changing apps
You need iOS and Android, which ProWritingAid doesn't list
Works across browsers, desktop apps and phone keyboards
Free plan is genuinely useful for spelling and grammar

Choose ProWritingAid if…

Fiction and long-form writers who want detailed style reports on a whole manuscript
Dozens of in-depth style and readability reports
Lifetime licence option instead of a subscription

What is Grammarly?

Grammarly checks spelling, grammar, punctuation, clarity and tone as you type, and adds generative AI for drafting and rewriting. It works in most places people write: a browser extension for Chrome, Safari, Edge and Firefox, desktop apps for Windows and Mac that hook into other programs, and keyboards for iPhone and Android. The free plan covers basic corrections and a small monthly allowance of AI prompts; the paid Pro plan adds full-sentence rewrites, tone adjustments, plagiarism and AI-text detection, and a much larger prompt allowance. Teams and enterprises get style guides, brand tones and admin controls. The company behind it renamed itself Superhuman in 2025 after buying the Superhuman email client, and enterprise features are increasingly sold as part of that wider suite, though Grammarly remains the product name. It is English-first; other languages are limited. The main concern people raise is privacy, since text is processed in Grammarly's cloud.

What is ProWritingAid?

ProWritingAid goes further than most checkers on style. Beyond grammar it runs reports on overused words, sentence length variety, pacing, dialogue tags, clichés, sticky sentences and readability, which makes it popular with novelists revising a full manuscript. Newer AI features add rephrasing, chapter critiques and Story Canvas tools for planning plots and getting feedback on ideas. It works in a web editor, as a browser extension, inside Google Docs and Microsoft Office, and through a desktop app that checks text in other programs. There is a limited free plan; Premium and Premium Pro are sold monthly, yearly or as a one-time lifetime licence, which is rare in this category and attractive to writers who dislike subscriptions. The depth is also its drawback: the volume of reports and highlights can feel overwhelming, and the interface is busier than Grammarly's. It suits people who want to study and improve their prose rather than just fix errors.

Side by side

Attribute	Grammarly	ProWritingAid
Pricing	Free plan + paid	Free plan + paid
Open source	No	No
Self-hostable	No	No
Platforms	Web, Windows, macOS, iOS, Android, Browser extension	Web, Windows, macOS, Browser extension
Best for	English writers who want corrections and AI help everywhere they type, without changing apps	Fiction and long-form writers who want detailed style reports on a whole manuscript
Status	Active	Active

Verified facts, compared

Facts both apps publish, checked on each vendor's own site.

Fact	Grammarly	ProWritingAid
Starting price	$12 per member/month, billed annually (Pro)	$10/month, billed yearly (Premium)