I still remember the moment I realized Grammarly was not enough. I was writing an email to a client in Madrid. The email was in Spanish — a language I speak but do not write perfectly. I ran it through Grammarly, which gave it a clean bill of health. Then I sent it to a Spanish-speaking friend for a quick review. She found four errors. Not minor stylistic preferences. Actual grammatical mistakes. Verb conjugations that were wrong. Gender agreement that was off. Prepositions that did not work the way I thought they did. Grammarly had missed all of them because, at the time, its Spanish support was limited. That is when I started looking for alternatives and found LanguageTool.

That was over two years ago. Since then, I have used LanguageTool across multiple languages — English, Spanish, French, and occasionally German. I have tested it against Grammarly, ProWritingAid, and the built-in grammar checkers in Google Docs and Microsoft Word. I have used the free version, paid for Premium, and integrated it into my browser, my documents, and my email. LanguageTool is not the most famous grammar checker on the market. But for writers who work in multiple languages, it fills a gap that more popular tools leave wide open.

This review is based on all that real-world use. I will show you exactly what LanguageTool can do, where it struggles, how much it costs, who should use it, and who should look elsewhere. If you write in more than one language and need a grammar checker that keeps up, this is the review you need.

What Exactly Is LanguageTool?

LanguageTool is an open-source grammar, style, and spell checker that has been under development since 2003. It was created by Daniel Naber and a community of contributors who believed that writing assistance should be available in as many languages as possible, not just English. The project started as a rule-based system and has evolved over two decades to incorporate AI-powered suggestions, style improvements, and advanced error detection.

The tool's defining feature is its multilingual support. LanguageTool checks grammar, spelling, and style in over thirty languages, including English, Spanish, French, German, Portuguese, Dutch, Polish, Russian, Arabic, Chinese, Japanese, and many more. For widely spoken languages, the support is deep and sophisticated. For less common languages, it varies but often provides useful basic checking where other tools offer nothing at all.

LanguageTool is available as a web editor, a browser extension for Chrome, Firefox, Edge, and Safari, a desktop app for Windows and Mac, and plugins for Google Docs, Microsoft Word, and LibreOffice. It also offers an API for developers who want to integrate grammar checking into their own applications. The Premium version adds advanced style suggestions, tone detection, and higher character limits. The company behind LanguageTool is based in Germany and operates with a strong commitment to privacy — an important differentiator in an era of AI tools that train on user data.

How I Tested LanguageTool for This Review

I have been using LanguageTool for over two years, but for this review I conducted a focused four-week testing period. Here is what I tested:

1. English grammar checking: Testing against deliberately error-filled text and comparing results with Grammarly and ProWritingAid.
2. Spanish grammar checking: Writing and correcting multiple Spanish emails and documents, verified by native speakers.
3. French grammar checking: Testing basic to intermediate French writing for error detection accuracy.
4. German grammar checking: Testing with German text to evaluate the tool's performance in its home language.
5. Style and tone suggestions: Evaluating Premium features for writing improvement beyond basic grammar.
6. Integration testing: Browser extension, Google Docs add-on, Microsoft Word plugin, and desktop app.
7. Privacy evaluation: Reviewing data handling policies and comparing with competitors.

I used both the free and Premium versions. I focused particularly on multilingual capabilities because that is LanguageTool's primary differentiator.

What LanguageTool Does Really Well

LanguageTool has several strengths that make it a compelling choice, especially for multilingual writers. Here is where it excels.

1. Genuine Multilingual Support That No Other Tool Matches

This is LanguageTool's killer feature and the reason it exists. The tool provides grammar and spell checking in over thirty languages. Not just basic spell checking — actual grammatical analysis with error detection, suggestions, and explanations. For English, Spanish, French, German, Portuguese, and Dutch, the support is deep and competitive with dedicated single-language tools. For other languages, the quality varies but LanguageTool is often the only option beyond basic spell checkers.

I tested LanguageTool's Spanish checking extensively. It caught verb conjugation errors, gender agreement issues, preposition mistakes, and accent mark problems that Grammarly missed entirely. When I had native Spanish speakers review the corrections, they confirmed that the suggestions were accurate and natural. For someone who writes in Spanish as a second language, LanguageTool provides a safety net that catches the kinds of errors non-native speakers make most often.

The tool's French and German support is similarly strong — which makes sense, given that the company is based in Germany and has invested heavily in major European languages. For writers who produce content in multiple languages, LanguageTool replaces the need for separate grammar checkers for each language. That consolidation alone can justify the subscription cost. For more on how AI tools support multilingual writing, I covered the landscape in my ultimate guide to AI writing tools.

2. Strong Privacy Stance

In an era where AI tools routinely collect user data for training, LanguageTool's privacy policy stands out. The company states clearly that text checked with the free version is not stored or used for training purposes. For Premium users, text is processed but not permanently stored. The tool can be used without creating an account for basic checking. The browser extension processes text locally where possible.

This privacy-first approach matters for several audiences. Journalists working on sensitive stories. Lawyers drafting confidential documents. Business professionals handling proprietary information. Academics working with unpublished research. Anyone who has hesitated to use AI writing tools because of data privacy concerns should look closely at LanguageTool. It offers capable grammar checking without the data collection practices that make some users uncomfortable with tools like Grammarly or ChatGPT. I reviewed another privacy-focused aspect of writing tools in my Grammarly vs ProWritingAid comparison.

3. Open-Source Foundation With Community Contributions

LanguageTool's open-source roots give it a different character from commercial alternatives. The rule-based system that powers the tool has been refined by hundreds of contributors over nearly two decades. This means the grammar rules are transparent, explainable, and continually improved by people who understand specific languages deeply. It is not a black-box AI making suggestions. It is a system built on linguistic knowledge.

The open-source nature also means that LanguageTool can be self-hosted. Organizations with strict data security requirements can run their own instance of LanguageTool on their own servers. This is not relevant for most individual users, but for enterprises, universities, and government agencies, it is a significant advantage.

4. Good Integration Across Platforms

LanguageTool offers browser extensions for all major browsers, add-ons for Google Docs and Microsoft Word, a desktop application, and an API. The browser extension works in email clients, content management systems, social media platforms, and most text fields on the web. The Google Docs add-on provides in-document checking that is smoother than copying and pasting into the web editor.

The integrations are not as polished as Grammarly's — the Google Docs experience in particular can feel slightly clunky compared to Grammarly's seamless integration — but they are functional and cover the essential writing environments. For users who work across multiple platforms and languages, the breadth of LanguageTool's integration ecosystem is a practical advantage.

5. Transparent, Explainable Suggestions

When LanguageTool flags an error, it tells you why. Each suggestion comes with a brief explanation of the grammar rule being applied. This is pedagogically valuable. Instead of just accepting corrections, you learn the underlying rules. Over time, you make fewer errors because you understand the patterns.

This contrasts with AI-powered tools that sometimes suggest changes without clear explanations. LanguageTool's rule-based foundation means the logic behind each suggestion is explicit. For language learners and non-native speakers, this educational dimension adds significant value beyond simple error correction.

Where LanguageTool Falls Short

LanguageTool is valuable, but it has real limitations. Here is where it struggles.

1. English Checking Is Not as Sophisticated as Grammarly

For English-only writers, LanguageTool's grammar checking is good but not best-in-class. Grammarly catches more errors, offers more nuanced style suggestions, and provides better tone and clarity feedback. LanguageTool's English checking is solid — it catches most grammatical errors, spelling mistakes, and basic style issues. But Grammarly's AI-powered suggestions are more sophisticated, particularly for clarity improvements, engagement, and tone adjustments.

If you write exclusively in English and want the most advanced grammar and style checking available, Grammarly remains the stronger choice. If you write in multiple languages or prioritize privacy, LanguageTool's English checking is good enough for most purposes while offering advantages Grammarly cannot match.

2. The Free Version Is Limited

LanguageTool's free version restricts you to 10,000 characters per check. For a short email or a social media post, this is fine. For a blog post, an article, or a document, you will hit the limit quickly and need to check your text in chunks. The free version also lacks advanced style suggestions, tone detection, and some of the more sophisticated error detection that Premium offers.

The Premium version removes character limits and adds advanced features. At $4.99 per month (billed annually) for the Individual plan, it is significantly less expensive than Grammarly Premium ($12/month) or ProWritingAid ($10/month). For the price, the Premium features are good value. But the free version's limitations mean that serious users will need to upgrade.

3. Style Suggestions Are Less Developed Than Competitors

LanguageTool's Premium style suggestions — rephrasing for clarity, improving word choice, adjusting tone — are useful but not as refined as Grammarly's or ProWritingAid's. The suggestions can sometimes feel mechanical, offering alternatives that are grammatically correct but stylistically awkward. The tool is stronger at catching errors than at improving prose.

For writers who want a tool that helps them become better stylists, not just more accurate grammarians, dedicated style tools like Hemingway Editor or the advanced features in ProWritingAid may complement LanguageTool well. Use LanguageTool for correctness across languages. Use another tool for style and readability refinement.

4. User Interface Feels Dated

LanguageTool's interface is functional but not modern or polished. The web editor looks like something from the early 2010s. The browser extension popup is utilitarian. The Google Docs add-on works but has occasional lag and formatting issues. Compared to Grammarly's sleek, seamless interface, LanguageTool feels like a tool built by engineers rather than designers.

This is a cosmetic issue that does not affect functionality. But for writers who spend hours in their tools, the user experience matters. If you value aesthetics and seamless integration, Grammarly provides a more pleasant experience. If you prioritize multilingual capability and privacy, LanguageTool's functional interface is a trade-off worth accepting.

5. AI Rewriting Features Are Still Maturing

LanguageTool has recently added AI-powered rewriting features that suggest alternative phrasings for entire sentences. This is a step toward competing with tools like Wordtune and QuillBot. However, the rewriting feature is not yet as sophisticated as dedicated rewriting tools. The suggestions can be hit or miss — sometimes improving clarity, sometimes offering awkward alternatives, sometimes missing the mark entirely.

The AI rewriting is a bonus feature, not a reason to choose LanguageTool. If rewriting and paraphrasing are central to your workflow, dedicated tools like Wordtune or QuillBot are stronger choices. LanguageTool's core value remains its multilingual grammar checking.

LanguageTool vs. The Competition

LanguageTool competes in the grammar checking space with several strong alternatives. Here is how it stacks up.

LanguageTool vs. Grammarly

Grammarly offers more sophisticated English checking with better AI-powered style, tone, and clarity suggestions. Its interface is more polished and its integrations are more seamless. LanguageTool offers genuine multilingual support and stronger privacy protections. For English-only writers who want the best grammar and style checking, Grammarly wins. For multilingual writers or those who prioritize privacy, LanguageTool wins. Many writers use both: Grammarly for English writing, LanguageTool for other languages. I compared Grammarly with ProWritingAid in detail in this article.

LanguageTool vs. ProWritingAid

ProWritingAid offers deeper style analysis and more comprehensive writing reports than LanguageTool. It is a better tool for writers who want to understand and improve their writing patterns over time. LanguageTool offers multilingual support that ProWritingAid lacks. For English writers focused on style improvement, ProWritingAid wins. For multilingual writers who need grammar checking across languages, LanguageTool wins.

LanguageTool vs. Microsoft Editor

Microsoft Editor is built into Microsoft 365 and offers grammar and style checking in multiple languages. It is convenient for users already in the Microsoft ecosystem. LanguageTool offers more languages, more integrations, and stronger privacy. For casual users who write in Microsoft products, Microsoft Editor is a convenient built-in option. For serious multilingual writers, LanguageTool offers more depth and flexibility.

Pros and Cons Summary

Pricing Overview

*Prices shown are annual billing. Monthly billing is slightly higher. The Individual Premium plan at $4.99/month (billed annually) is one of the most affordable Premium grammar checkers available.

Who Should Use LanguageTool?

Based on my testing, here is who will benefit most from LanguageTool:

• Multilingual writers and translators: If you write in two or more languages regularly, LanguageTool's ability to check grammar across languages in a single tool is its strongest selling point. It replaces multiple single-language checkers.
• Non-native English speakers: The clear, explainable suggestions help language learners understand their mistakes. The multilingual support means you can check your native language and English in the same tool.
• Privacy-conscious professionals: Journalists, lawyers, researchers, and anyone handling sensitive content will appreciate LanguageTool's strong privacy stance and data handling policies.
• Organizations with data security requirements: The self-hosting option makes LanguageTool viable for enterprises, universities, and government agencies that cannot send text to third-party servers.
• Budget-conscious users who want Premium features: At $4.99 per month, LanguageTool Premium is one of the most affordable ways to get advanced grammar and style checking. It is significantly cheaper than Grammarly Premium or ProWritingAid.

Who Should Look Elsewhere?

• English-only writers who want the best checking available: Grammarly's English checking is more sophisticated. If you never write in other languages and do not prioritize privacy, Grammarly offers a better English editing experience.
• Writers focused on style improvement and deep analysis: ProWritingAid's comprehensive writing reports and style analysis go deeper than LanguageTool's style suggestions. For writers who want to study and improve their craft, ProWritingAid is the stronger choice.
• Users who want seamless, beautiful integrations: Grammarly's interface and integrations are more polished. If user experience and aesthetics matter to you, LanguageTool may feel rough around the edges.
• Those who primarily need AI rewriting: LanguageTool's rewriting features are not its strength. Wordtune or QuillBot are better choices if paraphrasing and rewriting are your main needs.

Tips for Getting the Most Out of LanguageTool

After two years of regular use, here are my best tips for using LanguageTool effectively:

1. Set your primary language correctly for each document. LanguageTool's automatic language detection is good but not perfect. Manually set the language for important documents to ensure the correct grammar rules are applied.
2. Use the Premium style suggestions for important writing. The free version catches errors. Premium helps you improve your writing beyond correctness. For client work, publications, or important communications, the upgrade is worth it.
3. Read the explanations for flagged errors. LanguageTool tells you why something is wrong. Taking five seconds to read the explanation helps you learn and avoid the same mistake in the future. This is the feature that improves your writing over time.
4. Combine LanguageTool with a style tool for English writing. Use LanguageTool for grammar checking across languages. Use Hemingway Editor or ProWritingAid for style and readability improvements in English. Each tool handles its specialty.
5. Install the browser extension for everyday writing. The extension catches errors in emails, social media posts, and web forms without requiring you to copy and paste into the web editor. It is the most convenient way to use LanguageTool for daily communication.
6. Check the community forums for language-specific advice. LanguageTool's community includes linguists and language enthusiasts who contribute rules and improvements. The forums are a good resource for understanding specific grammar questions.

My Experience After Two Years of Using LanguageTool

I started using LanguageTool because I needed a grammar checker that worked in Spanish as well as English. Two years later, it has become my primary grammar tool — not because it is the best at any single thing, but because it is good enough at everything I need.

For English writing, I still use Grammarly for important pieces where nuanced style suggestions matter. But for everyday English writing — emails, quick blog edits, social media — LanguageTool catches what I need it to catch. For Spanish writing, it is indispensable. It catches the conjugation errors, the gender mismatches, the preposition mistakes that I, as a non-native speaker, make constantly. My Spanish-speaking clients notice fewer errors in my communications. That matters professionally.

The privacy stance is a quiet but important advantage. I do not worry about what happens to my text when I use LanguageTool. For sensitive client communications and unpublished work, that peace of mind is valuable. In an era where AI tools are increasingly hungry for training data, LanguageTool's restraint is refreshing.

LanguageTool will not win awards for its interface. It will not impress you with AI-powered rewriting magic. But it will check your grammar reliably in more languages than any other tool, respect your privacy while doing it, and charge you a fair price. For multilingual writers, that combination is hard to beat.

Frequently Asked Questions

Disclosure: This review is based on my personal testing and experience over two years. I pay for the LanguageTool Individual Premium plan myself. This article contains no affiliate links for LanguageTool. Some other links on Vexaruno may be affiliate links, but this does not influence my ratings or opinions. I recommend tools I genuinely use and believe are worth your time.