The short version
- For a novel or other long manuscript: ProWritingAid. It has fiction reports on pacing, overused words and sensory detail, a Chapter Critique, and it works inside Scrivener and Atticus as well as Word and Google Docs.
- For everything you type, on every device: Grammarly. It runs on Windows, Mac, the web, iOS and Android, with browser extensions for Chrome, Safari, Firefox and Edge.
- For the lowest yearly price: ProWritingAid Premium at $120 a year, against $144 for Grammarly Pro. ProWritingAid also sells a lifetime licence; Grammarly does not.
On the BookBird Score, ProWritingAid leads 8.5 to 8.2. Both earn full Value points for their free plans and the same 26 of 30 for Features. ProWritingAid’s better Trustpilot rating outweighs Grammarly’s far higher search demand.
ProWritingAid vs Grammarly, side by side
| ProWritingAid | Grammarly | |
|---|---|---|
| BookBird Score | 8.5 | 8.2 |
| Value | 25 / 25 | 25 / 25 |
| Features | 26 / 30 | 26 / 30 |
| Reputation | 23.8 / 30 | 15.7 / 30 |
| Demand | 9.9 / 15 | 15 / 15 |
| Plans (USD) |
|
|
| Pricing | Free plan + paid plans, lifetime option | Free plan + paid plans |
| Free trial | Free plan instead | 7 days |
| Platforms | web, Windows, Mac, browser extension | Windows, Mac, web, iOS, Android, browser extension |
| Checklist | Grammar and spelling, Style and readability reports, Rewrite suggestions, Works inside Word, Google Docs or the browser, Fiction-specific analysis | Grammar and spelling, Style and readability reports, Rewrite suggestions, Works inside Word, Google Docs or the browser |
| Trustpilot | 4.2 from 734 reviews | 3.1 from 10,469 reviews |
| US searches a month | 18,100 (“prowritingaid”) | 2,740,000 (“grammarly”) |
| Full details | ProWritingAid: price and features | Grammarly: price and features |
Prices in USD as shown on each vendor’s site on October 2, 2026.
Price: the same month, a different year
Paid by the month, the two are level: ProWritingAid Premium and Grammarly Pro both cost $30. The difference shows up on longer billing. ProWritingAid Premium is $120 a year ($10 a month), and Premium Pro is $144 a year. Grammarly Pro is $60 a quarter or $144 a year. So a year of ProWritingAid’s basic paid plan costs $24 less than a year of Grammarly Pro, and its top plan costs the same.
ProWritingAid is the only one of the two with a lifetime licence: $399 for Premium or $699 for Premium Pro, paid once. The $399 Premium licence costs less than three years of Grammarly Pro at $144 a year, which comes to $432. ProWritingAid offers a 3-day money-back guarantee on its yearly and lifetime plans. Grammarly offers a 7-day trial of Pro. Grammarly also has an Enterprise plan with custom pricing, which an author working alone will not need.
Free plans
Both free plans check spelling and grammar. ProWritingAid’s free plan checks 500 words at a time, which means pasting a chapter in pieces. Grammarly’s free plan includes 100 generative AI prompts a month, against 2,000 on Pro. If you only need a grammar pass on short texts such as blurbs, emails and social posts, either free plan will do; for a full manuscript, the 500-word limit is the one to plan around.
What each one checks
ProWritingAid: reports for fiction
Beyond grammar, spelling and punctuation, ProWritingAid lists more than 25 writing reports, including pacing, overused words, sensory detail and readability. Chapter Critique gives feedback on a chapter, Story Canvas gives feedback on a story idea, and a comparison feature measures your writing against 90 fiction authors. You can set up your own style guide and dictionary, which helps with invented names in fantasy and science fiction. It has a Rephrase tool for rewriting sentences.
It works inside Microsoft Word, Google Docs, Scrivener and Atticus. That matters for authors, because it means you can check a manuscript in the app you draft or format it in. See our book writing software comparison for Scrivener and Atticus themselves.
Grammarly: checks everywhere
Grammarly covers spelling and grammar correction, tone detection and adjustment, full-sentence rewrites and fluency suggestions. It also lists plagiarism and AI-generated text detection, and citation consistency, which ProWritingAid’s feature list in our data does not mention. Its generative AI prompts can draft or rewrite text on request.
Its strength is reach. Grammarly runs on Windows, Mac, the web, iOS and Android, integrates with Google Docs and Microsoft Office, and has extensions for the four main browsers. If much of your writing happens on a phone or in a browser, from newsletters to Amazon author pages, it follows you there.
What neither one replaces
Neither tool replaces a human editor. Both flag issues and suggest fixes, and the judgement on structure, plot and character stays with you or the editor you hire. Our guide to copy editing vs proofreading explains which stage of editing software can cover and which needs a person.
Platforms and where they run
Grammarly is listed for Windows, Mac, the web, iOS and Android, plus a browser extension. ProWritingAid is listed for the web, Windows, Mac and a browser extension, with no mobile apps in the data we collected. For the Features score, that is the main difference: five of five platforms for Grammarly against three for ProWritingAid. ProWritingAid makes up the points on the checklist, where it is the only one of the two with fiction-specific analysis.
Reviews and demand
On Trustpilot, ProWritingAid has 4.2 stars from 734 reviews and Grammarly 3.1 from 10,469. Both profiles rate the product itself, so both count toward Reputation: 23.8 of 30 for ProWritingAid and 15.7 for Grammarly. We could not use G2, which blocked our requests.
Demand runs the other way. Grammarly is searched about 2,740,000 times a month in the US, ProWritingAid about 18,100. Grammarly takes the full 15 points for Demand, ProWritingAid 9.9.
Which one should an author choose?
Choose ProWritingAid if your main job is editing a book-length manuscript, especially fiction. The reports are built around the problems novelists look for, it plugs into Scrivener and Atticus, it costs less per year, and you can buy it once.
Choose Grammarly if you need checks across many short texts and devices, if you want plagiarism detection, or if you write on your phone.
Some authors use both: Grammarly’s free plan for everyday writing and ProWritingAid for the manuscript. For a free check of readability and passive voice before you pay for either, Hemingway Editor’s free online editor is in the table below, and our guide to active vs passive voice explains what it is flagging.
Other editing software we score
| Software | Score | Price from | Best for |
|---|---|---|---|
| Hemingway Editor | 6.8 | Free plan; paid from $19.99 one-time | Cutting long sentences and passive voice to a target reading level |
| AutoCrit | 6.2 | Free plan; paid from $15 a month (billed yearly) | Fiction reports that compare your manuscript with your genre |
Hemingway Editor focuses on readability: it grades text, highlights wordy sentences and passive voice, and lets you set a target reading level. Its free online editor costs nothing, and the desktop app costs $19.99 once. AutoCrit is a fiction-focused online editor that compares a manuscript against major genres and includes a Story Analyzer for character arcs and plot threads. Its Trustpilot profile has no reviews, so its score is calculated without Reputation.
How the BookBird Score works
Data collected on October 2, 2026 from each vendor’s own site, Trustpilot, and US Google search volumes (Google Ads data via DataForSEO). Nobody pays to be listed, and the score is never adjusted by hand.
- Value, 25 points. What one year costs a single author on the cheapest plan with a USD price. A one-time licence is spread over 3 years; phone-only editions are not counted. A free plan earns the full 25. Otherwise the points fall in a straight line from 25 at $0 to 5 for the most expensive product in the same category.
- Features, 30 points. Platforms 10 (Mac, Windows, web, iOS, Android), and a checklist 20 (Grammar and spelling; Style and readability reports; Rewrite suggestions; Works inside Word, Google Docs or the browser; Fiction-specific analysis), read from the vendor’s feature list. Only what the vendor’s pages state counts; a format they do not name earns nothing.
- Reputation, 30 points. The Trustpilot rating, weighted by review count: it is blended with a neutral 3.0 as if it had 20 extra reviews, so 4.6 from 120 reviews counts for more than 5.0 from three. Used only when the profile rates the product itself. When it rates the whole company, or there is no profile or no reviews, this part is left out and the score is taken over the other 70 points. G2 was not used: it blocked our requests, and we did not guess its numbers.
- Demand, 15 points. US searches a month for the product’s name, on a log scale against the most-searched product in the same category.
The score is the points earned divided by the points that could be checked, on a 10-point scale, rounded to one decimal. Scores compare products within one category, so the same app can score differently as a writing app and as a formatter. We did not test the apps; the score measures price, stated features, published reviews and search interest, not writing quality.
| Editing & grammar | Value /25 | Features /30 | Reputation /30 | Demand /15 | Score /10 |
|---|---|---|---|---|---|
| ProWritingAid | 25 | 26 | 23.8 | 9.9 | 8.5 |
| Grammarly | 25 | 26 | 15.7 | 15 | 8.2 |
Questions
Is ProWritingAid better than Grammarly for fiction?
For fiction, ProWritingAid has more of the checks novelists use: pacing, overused words, sensory detail, a Chapter Critique and a comparison with 90 fiction authors. Grammarly has no fiction-specific reports in its feature list.
Which is cheaper, ProWritingAid or Grammarly?
Monthly, they cost the same ($30). Yearly, ProWritingAid Premium is $120 and Grammarly Pro $144. ProWritingAid also has lifetime licences at $399 and $699.
Does ProWritingAid work in Scrivener?
Yes. ProWritingAid lists Microsoft Word, Google Docs, Scrivener and Atticus as apps it works inside.
Does Grammarly have a mobile app?
Yes. Grammarly is listed for iOS and Android as well as Windows, Mac and the web. ProWritingAid does not list mobile apps.
Is there a free trial?
Grammarly offers a 7-day trial of Pro. ProWritingAid does not state a trial; it has a free plan and a 3-day money-back guarantee on yearly and lifetime plans.