Free grammar checker
Grammar checker for spelling, punctuation and style
The isGenAI grammar checker finds spelling, grammar, punctuation and style mistakes in English and 25 other languages and lets you apply each correction with one click. Free, no account, up to 20,000 characters per check.
What it checks
Spelling: misspelled and mistyped words, with likely corrections. Grammar: subject–verb agreement, articles, verb forms, confused words such as their/there and its/it’s, and missing or doubled words. Punctuation and style: comma use, spacing, capitalisation, repeated words and wordy phrasing.
Suggestions come from the open-source LanguageTool rule engine. Treat them as suggestions: names, technical terms and deliberate stylistic choices can be flagged even when they are correct.
Checking one language often? The Spanish grammar checker and French grammar checker open preset to that language.
Before you submit
Proofread after applying fixes, since a correction can change meaning. If your school or publisher asks you to disclose AI help, the AI disclosure generator writes the statement, and the citation generator formats APA, MLA and Chicago references, including for ChatGPT, Claude and Gemini.
Grammar checker questions
Is the grammar checker free?
Yes. It is free with no account and no sign-up, for texts up to 20,000 characters per check. The open checking service it uses allows about 20 checks a minute from one connection.
Which languages does it check?
English (US and UK), French, German, Spanish, Portuguese, Italian, Dutch, Polish, Russian, Ukrainian, Catalan, Swedish, Danish, Greek, Romanian, Slovak, Slovenian, Japanese, Chinese, Persian, Arabic, Irish, Galician and Esperanto. Choose a language or let it detect one automatically.
Where is my text sent?
Your text goes from your browser straight to the public LanguageTool API (LanguageTool GmbH), which returns the suggestions. isGenAI does not receive or store the text you check here. Avoid pasting confidential material into any online checker.
Does this tell me if my text was written by AI?
No. Grammar suggestions say nothing about who wrote a text. To look for a statement of AI use or a named AI tool in a text, use the isGenAI AI text checker, which quotes the exact sentence it found.
How do I apply a suggestion?
Click a suggested correction under an issue and it replaces the highlighted words in your text. If you edit the text yourself, run the check again so the positions of the remaining suggestions stay accurate.