Free Grammar Checker (+ Guide)

What is a grammar checker?

A grammar checker is a tool that reads text, finds mistakes in spelling, grammar and punctuation, and suggests a fix for each.

This one also flags clarity issues, like a word written twice in a row.

How to check your grammar

What it checks

The marks come in four colors, one for each kind of mistake:

Each mark shows why it's there, and most offer the fix, so you learn the rule as you go.

The mistakes I see most, and how to fix them

These are the mistakes it catches most often:

• Their, there and they're – "they're" is "they are", "their" owns something, and "there" is a place.
• Its and it's – "it's" is "it is" or "it has", while "its" owns something, like a dog wagging its tail.
• Could of and should of – it's "could have", which sounds like "could of" when you say it fast.
• A and an – "an" goes before a vowel sound, so it's an example, an hour and a user.
• Alot – it's two words, "a lot".
• Too and to – "to" goes before a verb, as in "things to buy", while "too" means "also" or "more than enough".

Every one of these is marked with its fix, so one click puts it right.

A real example

Here's the blog paragraph from the Try button, with its mistakes left in:

The check marked five mistakes as soon as it loaded, and Fix all put them right in one click:

It missed two, "Its tempting" and "posts needs". Fix it with AI caught both, so for anything important, run both.

How your writing compares with real posts

A text with no mistakes can still be hard to read. So I measured real writing the same way this checker measures yours:

The numbers are the middle post of each kind. The blog posts include my own, and the newsletters, LinkedIn and X posts are ones that did well.

Pick what you're writing, and each of your numbers shows next to theirs, green when it sits where most of them do.

Long sentences and passive ones are marked in the text too, so you know which to shorten first.

Fix it with AI

When there's a lot to fix, or you want a different tone, Fix it with AI rewrites the text in one pass.

Pick a tone and the language you want it in.

The AI fixes the mistakes and keeps your facts and links. It also writes to the numbers of the kind of post you picked.

You see every word taken out and put in before you use it. Each person gets 10 AI fixes a day, and the check itself has no limit.

Is my text private?

The check runs in your browser, so your text isn't sent anywhere while it's checked.

It only leaves your computer when you press Fix it with AI, and I don't keep it.

This checker or Grammarly?

Both find mistakes. They fit different moments:

• Use this checker when you want a quick check with no account or install, or want to see how your writing compares with real posts.
• Use Grammarly when you want checks inside every app you write in. It works as a browser extension, a desktop and phone app, and inside Microsoft Office and Google Docs, with a free plan that needs an account.

Plenty of people use both: Grammarly while they type, and this checker before something goes out.

More free writing tools

When the mistakes are fixed and the writing still isn't right, these help:

• Paraphrasing tool – three new versions of a text.
• Sentence rewriter – five takes on a sentence that won't come out right.
• Text summarizer – a long text cut to its main points.
• AI humanizer – a draft that sounds like AI, rewritten to sound like you.

Each one runs on this site, free.

Grammar checker or spell checker?

A spell checker finds misspelled words. A grammar checker finds those too, and the mistakes in how words fit together.

If spelling is all you want, the spell checker shows spelling first, with the rest a click away.

Who is the grammar checker for?

It's for anyone who writes in English and wants it right the first time:

• How to start a blog – bloggers checking a post before it goes live
• LinkedIn text formatter – creators writing posts for LinkedIn and X
• Readability checker – anyone who wants to know how easy their writing is to read
• AI humanizer – anyone editing a draft an AI wrote
• Spell checker – anyone who only wants their spelling checked

And if English isn't your first language, the marks explain each rule, so you learn it as you fix it.