Grammarly vs LanguageTool vs ProWritingAid compared
Three AI writing assistants compared on languages, depth of feedback, AI rewriting and who each one is built for.
Grammarly, LanguageTool and ProWritingAid all check spelling, grammar and style, and all now include AI rewriting. Their strengths diverge: Grammarly is an everyday assistant across apps, LanguageTool is the strongest choice for writing in several languages, and ProWritingAid offers the deepest feedback for long-form and fiction writers.
The short answer
- Choose Grammarly for everyday writing in English across email, documents and websites, with tone suggestions and generative prompts.
- Choose LanguageTool if you write in several languages and want style guides for team consistency.
- Choose ProWritingAid for book-length projects and detailed reports on style, pacing and story.
Side by side
| Grammarly | LanguageTool | ProWritingAid | |
|---|---|---|---|
| Best for | Everyday English writing across apps | Multilingual writers and teams | Authors and long-form writers |
| Languages | Check supported languages | Many languages, detected automatically | Check supported languages |
| AI features | Tone suggestions, rewrites, generative prompts, AI-detection and humanizer agents | AI paraphrasing on Premium | Rephrase, Sparks, Story Canvas, Chapter Critique |
| Team features | Enterprise controls | Style guides for consistent wording | Document types and school programmes |
| Free option | Free plan with limited AI prompts | Free grammar checker | Free plan with daily limits |
Languages
LanguageTool is the clear choice for non-English or multilingual writing. It detects the language you write in and checks many languages, with Premium adding thousands of extra checks for English, French, German, Spanish, Portuguese, Dutch and Polish. If you write in other languages, check what Grammarly and ProWritingAid currently support.
Depth of feedback
Grammarly explains each suggestion and adds tone and rewrite help, which suits busy professionals. ProWritingAid goes further for long texts, with line-editing reports on repetition, pacing and readability, custom suggestions for over forty document types and AI critiques of chapters. LanguageTool’s Picky Mode adds stricter checks on punctuation, style and typography.
Privacy and AI detection
Because these tools read what you type, check privacy settings before using them on confidential material. Grammarly now includes an agent that estimates whether text looks AI-generated; such estimates are not proof of how a text was written and should not be used alone to judge someone’s work.
How to decide
- Run the same 500-word sample through each free plan.
- Count the useful suggestions versus the ones you would reject.
- If you write in other languages, test them specifically.
- For long projects, compare ProWritingAid’s reports with your editor’s notes.
- Check which apps and browsers each tool works in for your daily setup.
GrammarlyWriting
LanguageToolWriting
ProWritingAidWriting
WordtuneWriting
Hemingway EditorWriting
DeepLWritingTools to explore
Sources
Official vendor pages consulted for this analysis in October 2026. Plans, limits and features change: check the vendor’s page before you buy.
- Grammarly: official site grammarly.com
- Grammarly: plans grammarly.com
- LanguageTool: official site languagetool.org
- LanguageTool: pricing languagetool.org
- ProWritingAid: official site prowritingaid.com
- ProWritingAid: pricing prowritingaid.com