I’ve been running Grammarly, ProWritingAid, and LanguageTool side-by-side for about a month on the kind of writing I actually do: client emails, technical docs, a half-finished book manuscript, and the occasional Slack post I overthink. None of them are magic, and the “best” one depends entirely on what you’re writing and how much you trust a machine to second-guess your prose. For the broader landscape of AI writing tools including Claude, ChatGPT, and Jasper, see our best AI writing tools roundup.
Here’s what I found after dragging the same paragraphs through all three — repeatedly, across different surfaces (web editor, browser extension, desktop app, API where available) — and paying attention to what they caught, what they missed, and what they got wrong.
Quick Verdict
If you write in a browser all day: Grammarly is still the smoothest. The Chrome extension Just Works in Gmail, Notion, Linear, and pretty much anywhere else, and the underlying model feels noticeably better at context than it did a year ago. Premium runs $144/year.
If you write long-form and want actual feedback, not just fixes: ProWritingAid. Its style reports are genuinely useful for manuscripts and long essays, though the interface can feel like reading a lab report. $120/year, or $399 lifetime if you’re committed.
If you write in multiple languages or care about where your text gets sent: LanguageTool. ~$59/year, open-source core, EU servers, self-hostable. The suggestions aren’t as sophisticated, but the privacy story is the cleanest.
How I Tested
No fake benchmark theater. I spent roughly a month using each tool on real work:
- A 2,500-word consulting report (business voice, lots of hedging)
- Two chapters of fiction with deliberately loose prose
- Marketing copy where “correct” and “good” are often in tension
- API docs full of code blocks and jargon
- Emails from a colleague who’s a non-native English speaker, to see how each tool handled L2 writing patterns
I also seeded documents with known error types — comma splices, subject-verb disagreements, dangling modifiers, commonly confused words — to see what got caught. Not a formal test set, but enough to notice real gaps.
Grammarly: The Default That Earned It
Grammarly’s 2026 update quietly swapped in a much stronger underlying model. Suggestions feel less rule-based and more aware of what you’re actually trying to say. Ask it to edit a sentence with a technical term like “sharded Postgres replica” and it no longer tries to “correct” the jargon into nonsense, which used to happen.
What it actually does well
- Context handling is the biggest jump. It picks up tense inconsistencies across multi-sentence spans, which rule-based checkers miss entirely.
- Tone detection is more useful than it sounds. Not because it’s profound — it’s pretty basic — but because seeing “this sounds frustrated” on a Slack message you’re about to send is a helpful speed bump.
- Universal coverage. Works in Gmail, Google Docs, Notion, Linear, Figma comments, Slack, and basically anywhere else you type. This is the feature you stop noticing, and that’s the point.
- Plagiarism checker (Premium only) actually found most matches when I tested it with slightly-paraphrased chunks from public blog posts. It missed a couple that had been reworded enough.
Where it genuinely falls down
It over-corrects creative writing. The moment you try to write with any rhythm — intentional fragments, run-ons for pacing, comma splices as a stylistic choice — Grammarly turns into a schoolteacher. You can set the goals to “creative,” but it still flags things it shouldn’t. If you write fiction, you will spend meaningful time dismissing its suggestions. For a tool that’s better at creative long-form, Claude outperformed every grammar checker we tested in our AI writing tools comparison.
No offline mode. Everything goes to Grammarly’s servers. For most people this is fine; for anyone writing anything remotely confidential (legal drafts, internal HR stuff, pre-announcement product docs), this is a hard no. Your corporate InfoSec team may already block it. If you’re dealing with legal documents, see our AI legal tools roundup for purpose-built options.
It’s the most expensive and the gap is real. $144/year for Premium, and the Business plan requires three seats minimum, which is annoying for a two-person shop.
Pricing:
- Free: spelling, basic grammar, tone hints
- Premium: $12/month billed annually ($144/year)
- Business: $15/user/month, 3-user minimum
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ProWritingAid: The One Writers Actually Learn From
ProWritingAid is built for a different job. Grammarly tells you what’s wrong; ProWritingAid tells you what your writing is like. There’s a difference, and if you care about the difference, this is your tool.
What it actually does well
- The reports are the product. Readability, sentence length variation, overused words (“just,” “really,” “that”), passive voice distribution, pacing in fiction. Running a 5,000-word chapter through it feels like getting notes from an editor who doesn’t sleep.
- Scrivener integration is the best in the category, and if you’re a novelist, this alone is the reason to pick it.
- Desktop app works offline, which matters if you’re writing on planes or in cafes with garbage wifi.
- Explanations teach you things. The sticky commas rule, the “weak verb” detector, the echo-word highlighter — these improved my writing habits over a few weeks in a way Grammarly never did.
Where it genuinely falls down
The interface is dated and kind of clunky. It feels like Windows-era software dressed in a modern theme. The web editor is slow, and running multiple reports on a long document can make you wait 5+ seconds per analysis. On a 10,000-word chapter I had to go get coffee.
It’s overwhelming if you just want grammar. If your use case is “fix typos in my emails,” you will hate this tool. Every report you enable adds another layer of squiggly lines, and the default view can look like a warning console.
Plagiarism is tacked-on. Premium+ includes checks, but it’s a credit-based system and noticeably weaker than Grammarly’s.
The Chrome extension is fine, not great. If you live in Gmail and Notion, this isn’t where it shines. Writing directly in its editor or via Scrivener/Word is where it actually earns its keep.
Pricing:
- Free: 500 words at a time, limited reports
- Premium: $120/year — full reports, all integrations
- Premium+: $144/year — adds plagiarism checks
- Lifetime: $399 one-time (the math favors this if you plan to stick with it more than ~3 years)
LanguageTool: The Honest Budget Pick With Real Limits
LanguageTool is the one I most want to love and most frequently get annoyed by. The open-source core, the EU hosting, the 30+ language support, the self-hosted option for paranoid teams — all of it is genuinely differentiated. And then you use it, and the suggestions are noticeably less smart than the other two.
What it actually does well
- Multilingual is the real sell. I tested German and Spanish alongside English, and it’s the only one of the three that treats non-English as a first-class citizen rather than a checkbox.
- Privacy story is the strongest. You can run LanguageTool on your own infrastructure with a docker container. For agencies handling NDAs, this is meaningful. Grammarly and ProWritingAid can’t offer this.
- Cheapest by a lot. $59/year for Premium. If you write in English and don’t need style coaching, the per-dollar value is hard to beat.
- Decent API with reasonable rate limits for developers who want to build grammar checking into their own tools.
Where it genuinely falls down
The suggestions feel a generation behind. On ambiguous or context-dependent errors, it frequently either missed them or flagged the wrong thing. On a paragraph where Grammarly correctly rewrote a tangled sentence, LanguageTool shrugged. If you’re used to how much Grammarly has improved recently, LanguageTool feels like grammar checking from 2022.
No plagiarism check at all. Not a downside for everyone, but if you’re a student, this disqualifies it immediately.
Style coverage is thin. It’s a grammar checker, not a writing coach. Don’t expect the readability reports or rhythm analysis you get from ProWritingAid — those just aren’t there.
The UI is functional but unloved. It works, but you can feel the open-source project energy — things are one more click away than they need to be.
Pricing:
- Free: 20,000 characters per check, fewer rules
- Premium: $4.92/month billed annually (~$59/year)
- Teams: $6.58/user/month
Head-to-Head Comparison
| Feature | Grammarly | ProWritingAid | LanguageTool |
|---|---|---|---|
| Strength | Context-aware grammar, ubiquity | Style reports, long-form analysis | Multilingual, privacy, price |
| Weakness | Price, over-correction, no offline | Slow, dated UI, overwhelming | Weaker suggestions, thin style |
| Grammar quality | Strongest in testing | Close second | Noticeably behind on nuance |
| Style feedback | Light | Deepest available | Minimal |
| Languages | English-focused | English-focused | 30+ |
| Plagiarism | Yes (Premium) | Yes (Premium+) | No |
| Offline | No | Yes (desktop app) | Limited / self-host |
| Integrations | 500+ sites/apps, strong mobile | Best Scrivener support, Word add-in | Browser extensions, Google Docs |
| Starting price | $144/year | $120/year | $59/year |
The Pricing Reality
If you use your grammar checker daily and it saves you 10 minutes, Grammarly’s $144/year is trivially worth it. If you use it for a few weekly reports, LanguageTool’s $59/year is plenty. ProWritingAid’s lifetime license at $399 pays back against the annual plan in a little over three years — reasonable if you’re confident you’ll stick with it.
The one pricing trap to watch: Grammarly Business requires three seats. If you’re a two-person team or solo with a contractor, you’re either paying for a phantom seat or dropping to individual Premium.
Where Each One Actually Belongs
Pick Grammarly if: you write in a browser across ten different tools every day, you want the fewest false positives on standard business prose, and you don’t care that your text gets sent to their servers. This is the default for a reason.
Pick ProWritingAid if: you write long-form — books, essays, research, long-form marketing — and you want something that will tell you your pacing drags in chapter four rather than just fix your commas. Writers on Scrivener should stop reading and go download it. For academic and research writing specifically, also see our guide to AI tools for academic writing.
Pick LanguageTool if: you write in multiple languages, your company cares about data residency, you want to self-host, or you just need a solid grammar checker without paying Grammarly money. Go in knowing the suggestions are less sophisticated — that’s the tradeoff you’re buying.
The Honest Tier List
I don’t think any of these tools is bad. But if you pushed me to rank them without hedging:
- Grammarly — best grammar quality, best coverage, worst price, will annoy creative writers.
- ProWritingAid — best for the specific job of improving long-form writing, worst interface of the three, best value over the long run if you buy the lifetime license.
- LanguageTool — clearly the weakest on suggestion quality, clearly the strongest on price and privacy, and the only real option if English isn’t your only language.
LanguageTool being third isn’t a knock — it’s a different product serving a different need. But if you’re writing only in English and quality of suggestions matters more than price, it’s genuinely a step behind.
FAQ
Is Grammarly’s context understanding actually better now? Yes, noticeably. The 2026 update clearly uses a stronger model underneath, and you can feel it in sentence-level rewrites. That said, “better” isn’t “correct” — it still confidently rewrites things you wrote correctly. Always read the suggestion before accepting it.
Can any of these replace a human editor? No. They catch errors well and make OK suggestions, but they don’t understand argument structure, audience, or when a rule should be broken. Use them as a first pass, not a final one. This is especially true for fiction — a grammar checker does not know why your comma splice is load-bearing.
Which one is best for non-native English speakers? LanguageTool for the language coverage, Grammarly for the explanations. I’d lean Grammarly if English is your main output language and you want to improve — its explanations are more educational. LanguageTool if you’re regularly switching between languages.
Do these work offline? Only ProWritingAid, via its desktop app. Grammarly is online-only. LanguageTool can be self-hosted if you want offline-ish behavior, but the hosted product needs a connection.
What about privacy for sensitive documents? If you’re writing anything under NDA, don’t paste it into Grammarly. LanguageTool’s self-hosted option is the only truly safe choice in this list. ProWritingAid’s desktop mode is a middle ground — it processes locally, though cloud features still sync when enabled.
How do they handle creative writing? Grammarly is the most aggressive; expect to dismiss a lot. ProWritingAid is more useful because its reports treat style as something to understand rather than eliminate. LanguageTool mostly stays out of your way, which, depending on your temperament, is a feature.
Final Take
If I had to keep one: Grammarly, for the coverage and the fact that it works everywhere I write. But I have ProWritingAid installed alongside it because they do different jobs, and on any serious piece of writing longer than a blog post, I end up running it through ProWritingAid’s reports before I’m done.
LanguageTool is the one I recommend most often to people who ask “which should I use?” because for a surprising number of people, the answer is you do not need what Grammarly is selling, and $59 vs $144 matters.
Start with the free tier of whichever one fits your use case best. All three have usable free versions, and a week of real use will tell you more than any comparison post.
Try Grammarly Free → · Try ProWritingAid → · Try LanguageTool →
Recommended Tools & Resources
If you’re exploring this topic further, these are the tools and products we regularly come back to:
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