The question shows up in a new Reddit thread every few weeks: "Is LanguageTool actually as good as Grammarly, or am I just saving money?" The honest answer is that both are true at once, depending on what you write and which language you write it in. LanguageTool and Grammarly are built on different philosophies — one is a transparent rule engine that grew a neural layer, the other is a neural assistant that answers to nobody — and the right choice comes down to four concrete differences, not vibes.
A disclosure up front: we build AmberPen, a proofreading API for developers, so we spend our working lives measuring grammar checkers on public benchmarks. We don't sell a consumer app and have no affiliate links here. LanguageTool is a tool we respect enough to compare ourselves against publicly, and where Grammarly wins below, we say so.
The short version
- Grammarly is the better English-only writing assistant: smoother suggestions, better tone and clarity rewrites, runs everywhere (browser, Office, Google Docs, mobile keyboards), and its paid tier adds plagiarism checking and generative AI features.
- LanguageTool is the better grammar checker per euro: comparable everyday-error detection in English, real grammar support in 30+ languages, a genuinely useful free tier, roughly half the subscription price, EU hosting, and an open-source core you can self-host.
If you write only English, mostly short professional text, and budget isn't the issue — Grammarly is the path of least resistance. If you write in more than one language, want a free tier that isn't a demo, care where your text is processed, or just refuse to pay $30/month — LanguageTool is the obvious pick. The rest of this article is the evidence for that summary.
1. Correction quality: the same job, two engines
Both tools comfortably catch the mechanical 90% — subject-verb agreement, doubled words, comma splices, its/it's, their/there. The differences live in the remaining 10%.
Grammarly's engine is neural and conservative. Its suggestions have a high hit rate: when it underlines, it's almost always right. The deliberate trade-off is recall — it skips borderline cases rather than risk a wrong flag. Its real strength is the layer above grammar: fluency rewrites, tone detection, formality adjustment, clarity rewording. No other consumer tool matches it there.
LanguageTool's engine is a hybrid: thousands of hand-written rules plus statistical and neural components. The rules give it two edges. First, transparency — every flag comes with the rule that fired it and an explanation, which makes it a better teaching tool. Second, multilingual depth — German comma rules, French agreement, Spanish clitics are encoded by people who speak those languages, which is why it outperforms Grammarly-style tools outside English.
The honest weaknesses, both directions: Grammarly is English-only, full stop. If you write a paragraph of German inside an English document, it shrugs. LanguageTool's English style suggestions are thinner — it flags fewer "this sentence is technically fine but weak" cases, and its rewrites are more mechanical. On raw English-error detection the two are closer than either fan base admits; on style coaching, Grammarly is meaningfully ahead; on everything multilingual, LanguageTool has no real competition from Grammarly at all.
Neither vendor publishes results on the standard academic benchmarks (JFLEG, CWEB) used to measure correction quality. If measured accuracy is your deciding factor, the only benchmark that matters is your own: run a week of your real writing through both free tiers and count accepted suggestions.
2. Pricing, August 2026
| LanguageTool | Grammarly | |
|---|---|---|
| Free tier | Genuinely useful — ~10,000 characters per check, browser + editor integrations, basic corrections | Useful — basic corrections, limited rewrites, English only |
| Premium entry | ~€4.99/mo billed annually (~€19.99 monthly) | $12/mo billed annually ($30 monthly) |
| Team plans | Per-seat, cheaper | Business per-seat, pricier |
| Self-host option | Yes — open-source core, free | No |
| Payment model | Subscription | Subscription |
Prices are list rates as of August 2026; both vendors run discounts, so verify before committing. But the shape is stable: LanguageTool costs roughly half of Grammarly at the annual tier, and its monthly tier doesn't carry Grammarly's punishing $30 rate.
The free tiers deserve emphasis. Grammarly's free tier is fine for casual English email. LanguageTool's free tier is one of the most generous in the category — 10,000 characters per check is enough for most essays and articles, which makes it the default answer to "is there a free Grammarly alternative that isn't crippled?" We covered that broader landscape in the 9 best Grammarly alternatives.
3. Privacy: EU hosting vs US cloud
This is the difference that settles the choice for a growing slice of users.
LanguageTool is a German company, hosts in the EU under GDPR, states that it doesn't train on your text, and — decisively — publishes its core engine as open source. If you want zero data exposure, you can run the LanguageTool server on your own machine or in your own cloud and keep Grammarly-class checking with nothing leaving your network. That self-hosted route has real costs and a real quality ceiling, which we priced honestly in the true cost of self-hosting a grammar checker.
Grammarly is a US company; your text goes to its servers under its retention policy. It offers enterprise admin controls and has a solid security record, but there is no self-host, no region pinning for individuals, and no way to inspect what the model does with your sentences. For most people that's fine. For anyone under a data-processing agreement, writing confidential drafts, or simply uncomfortable with the arrangement, it isn't.
4. Integrations: Grammarly's home turf
Credit where due: Grammarly's surface area is best-in-class. Chrome, Safari, Edge, Firefox; system-wide Windows and Mac apps; Microsoft Office; Google Docs; iOS and Android keyboards. It is already wherever you write.
LanguageTool covers the same major surfaces — browser extensions, Office and Google Docs add-ins, desktop apps — and adds one Grammarly doesn't have: an open API and a documented on-premise server, which is why it's embedded inside products like Obsidian community plugins, Nextcloud, and various CMS workflows. Its Google Docs add-on is functional but less polished than Grammarly's, and its style suggestions in the browser extension arrive a beat slower.
For a solo writer this is a wash favoring Grammarly. For a team that needs checking inside its own software, LanguageTool is the only one of the two that even plays — which is the pivot to the case neither consumer tool covers.
5. What neither tool does: corrections inside your own product
Both are closed, consumer-facing assistants. If you are building a product — a note-taking app, a support console, an LMS, a CMS — and you want corrections rendered in your UI, under your brand, with your vocabulary, neither sells you that:
- Grammarly operates a developer platform, but its APIs return writing scores and manage licenses, not corrections. We documented exactly what it does and doesn't return in what Grammarly's API actually offers.
- LanguageTool gets you closest: its open-source server has an HTTP API, and self-hosting it is a legitimate architecture — the tradeoffs article above covers when that wins. Its premium hosted API exists but is priced for volume and wraps the same rule engine with its recall ceiling.
If that's the wall you've hit, you're shopping in a different category: proofreading APIs that return structured edits — offsets, replacements, explanations — for your own UI to render. That's the category we build in, alongside Sapling and GrammarBot. The grammar checker API comparison covers the options with public benchmark data, and what you'll actually pay models the per-character billing. AmberPen's Starter plan is €5/month with 500K characters included, and a free test key shows the edit format in minutes.
Which one should you pick?
Choose Grammarly if you write exclusively in English, mostly short functional prose, and you value the tone/clarity assistant enough to pay for it. It's the best-polished consumer experience in the category.
Choose LanguageTool if you write in more than one language, want a free tier that does real work, prefer your text processed in the EU (or nowhere but your own server), or simply want 90% of the job for half the price. For most people asking the Reddit question, this is the answer.
Choose neither — and look at the API category — if you're a developer who needs corrections as structured data inside your own product. That's the only scenario where we can help directly, and it's a five-minute test.
Both Grammarly and LanguageTool offer workable free tiers. Run a week of your real writing through each, count the suggestions you actually accept, and keep the one whose advice you take. And if you're weighing LanguageTool against the rest of the field rather than just Grammarly, the head-to-head against ProWritingAid's long-form focus is in Grammarly vs ProWritingAid — the third corner of the triangle.