Free English grammar checker, offline

Korr checks English spelling and grammar on your device, with no account and no limit. It is built for the mistakes that grammar and spelling tools often let through: agreement at a distance, tenses, gerunds and the words that sound alike.

Try it in your browser Add to Chrome Download for Windows

Real examples, run through Korr

You writeKorr returnsWhy
She dont likes apples.She doesn't like apples.Missing apostrophe, and the verb after does stays in its base form
The results of the survey was surprising.The results of the survey were surprising.The verb agrees with results, not with survey
I look forward to hear from you.I look forward to hearing from you.In look forward to, to is a preposition: a gerund follows
We need more informations about the project.We need more information about the project.Information is uncountable
If I would have known, I would have come.If I had known, I would have come.The if clause of a past conditional takes the past perfect
I have seen him yesterday.I saw him yesterday.Yesterday dates the action: simple past
Its going to rain, so bring you're umbrella.It's going to rain, so bring your umbrella.It is, and the possessive your
He suggested me to take the train.He suggested that I take the train.Suggest takes a that clause, not an object plus infinitive

What Korr leaves alone, on purpose

When a sentence can be read two correct ways, Korr changes nothing. These are deliberate:

The team are winning.

Correct in British English, where collective nouns can take a plural verb.

Beside the river, we set up camp.

Beside and besides can both be right here; only the meaning decides.

We must insure that the data is safe.

Insure is accepted for ensure in American English.

The data suggest a warmer spring.

Data can be singular or plural; the author chooses.

Where it works

English is checked on the website, in the Chrome extension (Alt+Shift+C, also in Edge) and in the Windows app (Ctrl+Alt+C, in any program).

Measured, with the method

English accuracy is published with its method, including a benchmark written after tuning, where recall is lower and the page says so. See the numbers.

FAQ

Is Korr a free English grammar checker?

Yes. It is free, with no account, no subscription and no character limit, and the correction runs on your device.

Does it work offline?

Yes. After the first load the English engine stays available with no connection, and your text is never sent to a server.

Does it rewrite my sentences?

No. Korr corrects mistakes and lists every change so you can reject it. Rewriting styles are separate and optional.

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