What types of errors does it detect?

Grammar mistakes, spelling errors, punctuation issues, subject-verb agreement, tense errors, and readability suggestions.

Is it suitable for academic writing?

Yes. It catches common academic errors including comma splices, fragments, and word choice issues.

Is there a word limit?

No strict word limits. For very long texts, checking in sections gives the most accurate results.

Grammar Checker

Check your text for grammar, spelling, and punctuation errors. Powered by LanguageTool for accurate suggestions. Free, fast, and no signup required.

Language Your Text

What's actually checking your text

This tool is a front end for the public LanguageTool API, an open‑source proofreading engine that's been in development since 2003. LanguageTool works by running your text through thousands of hand‑written rules plus a statistical model; it catches spelling errors, common grammar slips, typography issues (double spaces, smart‑quote placement), and some style patterns. Your text leaves your browser only in this one step — a single request to api.languagetool.org — and the response is parsed locally into the highlights and suggestions you see. LanguageTool's privacy policy states that submitted text is not stored for the free API tier.

Where rule‑based checking shines

Subject–verb agreement ("The list of items are on the desk").
Confusable pairs (their/there/they're, its/it's, affect/effect, then/than).
Punctuation around quotation marks, comma splices, missing Oxford commas (configurable).
Repeated words and double spaces.
Straightforward spelling — with strong support for English, German, French, Spanish, Portuguese, Italian, and Dutch.

Where it won't help much

Rule‑based grammar checkers can't truly judge meaning. They won't flag a sentence that's grammatically fine but logically wrong, they miss context‑dependent word choice errors, and they can over‑flag stylistic decisions. LanguageTool is also noticeably less aggressive than Grammarly Premium on "style" suggestions — that's by design, because rule‑based false positives frustrate writers more than missed catches. If you want tone and clarity suggestions, run the tool as a first pass and then re‑read the text yourself.

Choosing the right dialect

Set English (US) for American audiences and English (UK) for British. The difference isn't just color/colour; it also affects date formats, punctuation conventions (US puts commas inside quotes, UK outside), and vocabulary flags (petrol vs gas). Auto‑detect works for clearly monolingual input but gets confused if you mix languages in one paragraph.

Limits and tips

The free LanguageTool API has a per‑request character limit (around 20,000) and a rate limit. For very long documents, check a chapter at a time. For sensitive material that you'd rather not send over the network at all, LanguageTool is also available as a local command‑line tool and as a LibreOffice extension — both do the same job fully offline.