LanguageTool
FreemiumOpen-source multilingual grammar and style checker supporting 30+ languages with browser extensions, API access, and AI-powered paraphrasing.
What does this tool do?
LanguageTool is a multilingual grammar and style checker that operates as both a browser extension and standalone web editor. It detects spelling errors, grammar mistakes, punctuation issues, and style problems across 30+ languages with automatic language detection. The tool uses pattern-based rules and AI-powered suggestions to catch common errors like subject-verb agreement, incorrect plurals, comma placement, and casing errors. Beyond basic corrections, it includes a paraphrasing feature powered by AI that can rephrase sentences to be more formal, simple, or concise. The platform emphasizes privacy—browser extensions don't store text—and integrates with popular applications like Google Docs, Microsoft Word, Outlook, and Slack, making it accessible across typical professional workflows.
AI analysis from Feb 23, 2026
Key Features
- Real-time spell checking with red underlines for typos and misspellings
- Grammar detection for subject-verb agreement, plural forms, and grammatical correctness
- Punctuation analysis distinguishing between optional and required commas in complex sentences
- Style improvement detection identifying overused phrases, redundant words, and improper word choice (blue underline)
- AI-powered paraphrasing with tone selection (formal, fluent, simple, concise)
- Personal dictionary for adding custom terms and proper nouns
- Writing statistics tracking productivity, error patterns, and improvement over time
- Automatic language detection and support for 30+ languages including English, Spanish, French, German, Portuguese, Russian, Polish
- Browser extensions for Chrome, Firefox, Edge, Safari with privacy-first architecture
- Native integrations with Microsoft Word, Google Docs, Outlook, Pages, and Slack
Use Cases
- 1Email and communication professionals ensuring error-free messages in Outlook and webmail before sending
- 2Content creators and bloggers catching style inconsistencies and redundant phrasing in real-time
- 3Non-native English speakers writing professional documents, essays, or business correspondence
- 4Academic writers using the tool to verify grammar in dissertations and research papers
- 5Multilingual teams writing in various languages with automatic language detection across documents
- 6Microsoft Word and Google Docs users integrating continuous spell-check into their primary writing tools
- 7Customer support and marketing teams maintaining consistent tone and eliminating embarrassing errors in public-facing content
Pros & Cons
Advantages
- Genuinely multilingual support with 30+ languages and automatic detection eliminates manual language switching
- Privacy-respecting browser extension that doesn't store text, differentiating it from competitors collecting user data
- Robust punctuation detection that differentiates between optional and required commas, handling complex sentence structures
- Paraphrasing tool with multiple tone options (formal, simple, concise) adds genuine value beyond error correction
- Extensive integrations with Word, Outlook, Google Docs, and native macOS/Windows apps create seamless workflows
Limitations
- Free tier limitations not clearly detailed on homepage—must create account to understand feature restrictions
- Pricing details completely absent from website; premium plan costs and feature differentiation unknown
- Limited transparency on accuracy claims; no comparison data against competitors like Grammarly
- Paraphrasing feature quality and reliability not demonstrated with examples or user reviews
- For specialized writing (legal, medical, technical), unclear whether tool handles domain-specific terminology effectively
Pricing Details
Pricing details not publicly available. Website mentions free account creation with features like Personal Dictionary, distraction-free editor, statistics tracking, and secure text storage. A 'Picky Mode' for advanced suggestions is referenced but whether it's free or premium-tier is unclear.
Who is this for?
Non-native English speakers writing professional content, academic researchers, multilingual teams, content creators and bloggers, customer support and marketing professionals, and anyone using Microsoft Word, Google Docs, or email clients as primary writing platforms. Organizations valued by BMW Group, European Union institutions, and media companies like Spiegel Magazine.