Grammar Checker

LanguageTool, self-hosted. The open-source grammar engine runs on our own infrastructure, so your text never reaches a third-party grammar service or a paid API.

Rewriting Mode

Professional: Business-appropriate. This mode does not split long sentences, or turn noun phrases back into verbs.

Original Text0 / 5,000
0 words0 chars<1 min

Where the Checking Actually Happens

This checker is a local LanguageTool server, queried over HTTP on our own network — not the paid remote LanguageTool API and not a language model.

Every Match Names the Rule That Fired

Each match comes back with the rule that fired, the offending span and up to three suggested replacements, so you can see why something was flagged instead of taking it on trust.

Automatic Correction Is Deliberately Timid

Automatic correction is deliberately timid: at most five fixes are applied to a document, only where LanguageTool offers exactly one replacement, and style-level and hint-level matches are skipped entirely so it will not quietly rewrite your voice.

The whole batch of fixes is discarded if it would change a number, a negation, or one of the protected spans holding your names and citations.

The Same Server Gates Every Rewrite

The same server also acts as a gate during rewriting: any candidate sentence that introduces a grammar error the previous version did not have is rejected.

If the server is unreachable, the tool says so — grammar checking reports as unavailable rather than silently passing everything.

Common Use Cases

  • Proofreading an email before you send it
  • Checking English written by a non-native speaker
  • A final pass over a document before publishing
  • Catching subject-verb agreement slips in a long report
  • Proofreading sensitive text you would rather not send to a third-party service

How It Works

1

Paste your text

Up to 5,000 characters of anything you want proofread.

2

Run the check

The text is sent to our own LanguageTool server, not an external service.

3

Read each match

Every issue names its rule and offers up to three replacements.

4

Apply or decide

Unambiguous fixes can be applied automatically; the rest are yours to judge.

Frequently Asked Questions

To a LanguageTool instance on our own infrastructure, over a local HTTP call. It is not the paid remote LanguageTool API, it is not a language model, and raw text is deliberately kept out of the logs.

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