If you write emails, reports, or essays in English and you live in Europe, you have probably asked the same question as thousands of students, freelancers, and office workers from London to Berlin: which AI writing assistant is actually worth using? Grammarly, LanguageTool, and DeepL Write are the three names that come up again and again — but they work very differently, cost very different amounts, and treat your data very differently too.
I spent several weeks putting all three through the same real-world tests: drafting client emails, polishing CVs, fixing academic paragraphs, and switching between English, German, and French. This comparison looks at what each tool does well, what it costs in euros, how it handles your privacy under GDPR, and — most importantly — which one deserves a place in your browser in 2026.
Meet the three contenders
Grammarly: the polished all-rounder
Grammarly is the biggest name in AI writing assistance, and it shows. Beyond basic spelling and grammar, it rewrites whole sentences for clarity, adjusts tone (confident, friendly, formal), checks for plagiarism, and even generates text with its built-in generative AI. It lives everywhere: a browser extension, a desktop app, Microsoft Word and Google Docs integrations, and a mobile keyboard.
For non-native English speakers — which includes most of us in continental Europe — Grammarly’s tone suggestions are genuinely useful. It catches the small awkwardnesses that make an email sound “translated” rather than natural. The downside? It is an American company, its most useful features sit behind the paywall, and the free plan is fairly limited.
LanguageTool: the European privacy champion
LanguageTool comes from Potsdam, Germany, and that origin shapes everything about it. It is open-source at its core, supports more than 30 languages (including excellent German, French, Dutch, Spanish, and Polish support), and offers something neither rival does: you can run it on your own server, so your text never leaves your infrastructure.
In daily use, LanguageTool is a superb proofreader. It catches grammar, punctuation, and style issues with impressive accuracy, and its multilingual checking is arguably the best of the three — you can even check mixed-language documents. It is less of a “rewrite my paragraph” AI and more of a meticulous editor, though its premium tier adds AI-powered rephrasing too.
DeepL Write: the multilingual specialist
DeepL Write comes from Cologne-based DeepL, the company behind the translator that millions of Europeans already trust. Write does one thing and does it beautifully: it rephrases your sentences to sound more natural. You write a clunky draft, and Write offers several polished alternatives, letting you pick the tone — from business-formal to friendly.
Its killer feature for European users is language coverage: Write works in English, German, French, Spanish, Italian, Portuguese, and Dutch, and it understands the nuances of each. If you regularly write in two or three languages, nothing else feels this smooth. The trade-off is a narrower feature set — there is no plagiarism checker and fewer integrations than Grammarly.
Feature-by-feature comparison
Correction accuracy. All three catch typos and basic grammar reliably. Grammarly goes furthest with contextual rewrites and tone analysis. LanguageTool is the most precise for German and French grammar rules. DeepL Write produces the most natural-sounding rephrasings, especially in German and French.
Tone and style help. Grammarly leads here with its tone detector and audience settings. DeepL Write’s alternative phrasings give you excellent stylistic control, though you choose manually. LanguageTool’s style rules are solid but more conservative.
Language support. LanguageTool supports 30+ languages — the clear winner for polyglots. DeepL Write covers seven European languages deeply. Grammarly focuses overwhelmingly on English, with only basic support for a handful of other languages.
Plagiarism checking. Only Grammarly includes a plagiarism checker (Premium plan). None of the three is primarily an AI detector, so do not buy them for that purpose.
Integrations. Grammarly works in the most places: browser, Word, Google Docs, email clients, mobile keyboard. DeepL Write offers browser extensions, a web app, and Microsoft 365 and Google Workspace integrations on paid plans. LanguageTool has browser add-ons, a desktop app, and plug-ins for Word, LibreOffice, and Google Docs.
Pricing: what you pay in euros
Prices shift with promotions, but the landscape in 2026 looks like this:
- Grammarly Free: basic grammar and spelling — genuinely useful, but no advanced rewrites. Premium costs around €12 per month on the annual plan (roughly €144 per year) and unlocks tone, clarity, and plagiarism features.
- LanguageTool Free: checks up to 10,000 characters per text — generous for everyday use. Premium is about €4.99 per month (€59.88 per year), adding AI rephrasing and longer texts. It is by far the cheapest premium option here.
- DeepL Write: the free version has usage limits; Write Pro costs around €8.99 per month and is also bundled into DeepL’s translation Pro plans, which is good value if you already use DeepL Translator.
For students and casual users, the free tiers of LanguageTool and DeepL Write cover most needs. Grammarly’s free plan feels the most restricted of the three.
Privacy and GDPR: where do your words go?
This matters more than most comparisons admit. A writing assistant reads everything you type — emails, CVs, contracts, medical letters. Under GDPR, you want a processor inside the EU/EEA with clear data policies.
- LanguageTool: based in Germany and GDPR-native. Texts are processed on EU servers, premium users get additional guarantees, and the self-hosted option means maximum control. The strongest privacy story of the three.
- DeepL: based in Cologne, Germany. DeepL states that texts from Pro users are never used to train its models and are deleted after processing. A very solid option for privacy-conscious Europeans.
- Grammarly: headquartered in the US. It offers GDPR-compliant data processing agreements for business customers and holds certifications like SOC 2 and ISO 27001, but your text is processed under US jurisdiction. If you handle sensitive client data, your company’s data policy may rule it out.
If privacy is a deciding factor, our guide to GDPR-friendly alternatives to popular AI tools goes deeper, and our explainer on how the EU AI Act affects everyday AI users covers the regulatory landscape.
Which one should you choose?
Choose Grammarly if you write mainly in English and want the most capable all-in-one assistant — especially for professional emails and long documents where tone matters.
Choose LanguageTool if privacy matters to you, you write in German, French, Dutch, or other European languages, or you want the best value: its premium plan costs less than half of Grammarly’s.
Choose DeepL Write if you switch between languages daily and want the most natural rephrasing. Pair it with DeepL Translator and you have the best multilingual writing setup available in Europe.
Honestly? Many European professionals end up with two: LanguageTool for everyday checking across languages, plus DeepL Write for polishing important texts. That combination costs less than Grammarly Premium alone — and keeps your data inside the EU.
Frequently asked questions
Can I use these tools for free? Yes. All three offer free plans that are genuinely useful for everyday writing. You only need to pay for advanced rewrites, longer documents, or team features.
Do they work in Google Docs and Microsoft Word? Grammarly and LanguageTool both integrate with Google Docs and Word. DeepL Write offers browser extensions plus Microsoft 365 and Google Workspace integrations on paid plans.
Which is best for writing in German? LanguageTool has the deepest German grammar rules, and DeepL Write produces the most natural German rephrasing. Grammarly is the weakest choice for German.
Are AI writing assistants allowed at European universities? It depends on the institution. Grammar and style checking is usually fine; generating whole assignments with AI typically is not. Always check your university’s policy.
The verdict
There is no single winner, because these tools solve different problems. Grammarly is the most powerful English writing coach. LanguageTool is the smartest choice for privacy and multilingual Europeans on a budget. DeepL Write is the finest rephrasing engine for people who live between languages. Match the tool to your actual writing life — your emails, and your data, will thank you.
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