LanguageTool

LanguageTool is a powerful open-source AI grammar checker that supports over 30 languages and dialects, making it one of the most multilingual writing assistants available. It catches grammar, spelling, punctuation, and style errors while offering AI-powered paraphrasing capabilities.

Key Capabilities

LanguageTool performs over 20,000 checks for major languages including English, German, French, Spanish, Dutch, Polish, and Portuguese, catching everything from basic typos to complex grammatical errors and style issues. The Premium tier adds AI-powered sentence paraphrasing that can adjust tone to be more formal, fluid, or concise. The tool also detects incorrect names, numbers, and formatting inconsistencies. It integrates seamlessly with Google Docs, Microsoft Word, LibreOffice, Gmail, and all major web browsers.

Who Should Use LanguageTool

LanguageTool is ideal for multilingual writers, international teams, academics, and anyone who writes in languages beyond English. Its open-source foundation and extensive language coverage make it particularly appealing to organizations with diverse linguistic needs. Students and professionals who value privacy will appreciate the option to self-host the tool.

Getting Started

Visit languagetool.org and start using the free version immediately by pasting text or installing the browser extension. The free tier supports up to 10,000 characters per check. Upgrading to Premium provides expanded character limits (up to 100,000), AI paraphrasing, style suggestions, and advanced error detection.

Pricing & Accessibility: The free plan supports up to 10,000 characters per check with basic grammar and spelling. Premium costs $4.99/month (billed yearly at $59.90) and includes advanced checks, AI paraphrasing, and expanded limits. Teams pricing starts at $9.48/month for 2 users. An open-source version is available for self-hosting.

Why Consider LanguageTool: With support for 30+ languages, an open-source foundation, and an extremely affordable Premium plan, LanguageTool offers the best multilingual grammar checking value available, especially for non-English writers who are underserved by most competitors.