LanguageTool is an AI-powered grammar checker and rewriter that detects errors traditional spell checkers miss, such as grammar issues, common confusions, and punctuation mistakes. It also offers style suggestions, synonym replacements, sentence simplification, and replacements for common expressions with more formal alternatives. LanguageTool supports over 25 languages, including English, Spanish, French, German, Russian, and more. It's free to use and works with virtually any website or platform.