LanguageTool

LanguageTool is an open-source grammar, style, and spell checking tool developed by LanguageTooler GmbH, a German company based in Potsdam. Originally created by Daniel Naber in 2003 as a research project, it has evolved into one of the most capable multilingual writing assistants available. With support for over 30 languages and a strong commitment to user privacy, LanguageTool offers a compelling European alternative to Grammarly and other US-based writing tools.

Multilingual Excellence

Where LanguageTool truly shines is its multilingual support. While Grammarly focuses primarily on English, LanguageTool provides comprehensive checking for over 30 languages including German, French, Spanish, Portuguese, Dutch, Polish, Russian, and many more. For each language, the tool offers grammar rules, style suggestions, and spell checking tailored to the specific linguistic characteristics of that language.

The multilingual capability is particularly valuable for Europeans who regularly write in multiple languages or work with international teams. LanguageTool can detect the language automatically and apply the appropriate rules, or you can specify the language variant you are writing in (e.g., British vs. American English, European vs. Brazilian Portuguese). This makes it the ideal tool for multilingual professionals and businesses operating across European markets.

Grammar and Style Checking

LanguageTool detects a wide range of writing issues including grammatical errors, spelling mistakes, punctuation problems, and style issues. The free tier catches many common errors, while the Premium version adds thousands of additional rules for more sophisticated checking. Premium features include detection of style issues, word repetition, redundant phrases, and suggestions for clearer writing.

The tool uses a combination of rule-based checking and machine learning to identify errors. This hybrid approach provides reliable detection of clear grammatical errors while also catching more nuanced issues that pure rule-based systems might miss. Unlike some competitors that rely heavily on AI, LanguageTool maintains transparency about its corrections with clear explanations for each suggestion.

Privacy and Data Protection

Privacy is a fundamental principle of LanguageTool's design. The company is based in Germany and subject to strict EU data protection laws. Text submitted for checking is encrypted in transit and processed on European servers. The company explicitly states that it does not sell user data and does not use text for advertising purposes.

For maximum privacy, users can self-host LanguageTool on their own infrastructure. The open-source core allows organizations to run the checking engine locally, ensuring that sensitive text never leaves their network. This is particularly valuable for law firms, healthcare organizations, government agencies, and businesses handling confidential information.

Browser Extensions and Integrations

LanguageTool offers browser extensions for Chrome, Firefox, Safari, and Edge that check your writing across websites. The extensions work on email services, social media, content management systems, and virtually any text field you encounter online. Unlike some competitors, LanguageTool's extensions are lightweight and do not slow down browser performance.

Desktop add-ins are available for Microsoft Word, LibreOffice, Google Docs, and other applications. These integrations bring LanguageTool's checking capabilities directly into your word processor, showing suggestions inline without requiring copy-paste to a web interface. An API is also available for developers who want to integrate grammar checking into their own applications.

Pricing and Value

LanguageTool offers a generous free tier that includes basic grammar, punctuation, and spell checking with a 10,000 character limit per check. This is sufficient for many casual users and allows thorough evaluation before subscribing. The Premium tier, starting at 4.99 euros per month when billed annually, removes character limits and adds advanced style checking, word choice suggestions, and team features.

Compared to Grammarly Premium, LanguageTool Premium is significantly more affordable while offering comparable features plus superior multilingual support. For organizations, team plans provide centralized billing and management. The combination of competitive pricing, strong features, and European data protection makes LanguageTool an excellent choice for privacy-conscious writers.