Grammar and spelling checker · Free · Nothing uploaded
Grammar Checker
To check grammar without uploading anything, paste your text into the box. This checker runs 21 named rules in your browser, for misspellings, a or an, could of, their is, he don’t, repeated words and spacing, and lists likely mistakes and style notes apart from errors. Your browser’s own spell check underlines unknown words.
The example on the tool: 14 findings, of which 10 errors are fixed by one press of Fix all errors.
Nothing typed yet. The text is kept in this browser only.
- Errors
- 0
- To check
- 0
- Style
- 0
- Words
- 0
- Sentences
- 0
Findings
Findings are listed here, in the order they appear.
Your text, marked
Errors underlined, checks dotted, style dashed.
Paste or type text. Each finding is labelled an error, a check or a style note, with its rule and a fix where there is one; nothing leaves this browser.
A grammar checker compares a text with rules of written English and points out the places that break them. Rule-based checkers, like this one, match patterns of words; AI checkers send the text to a language model that reads whole sentences.
- No sign-up
- Nothing uploaded
- No word limit
- Every rule named
- Works offline
Key facts
| Detail | Answer |
|---|---|
| Price | Free, no sign-up, nothing to install |
| Rules | 21, each named, in three kinds: error, check, style |
| Spelling | Your browser’s dictionary, plus 163 common misspellings |
| Phrases | 39 misheard, 55 wordy |
| US and UK | 72 word pairs and 36 -ize verbs |
| Length | No limit set; up to 500,000 characters kept |
| Language | English |
| Where the text is kept | This browser only |
How to check your grammar
Paste the text, fix the errors, decide on the checks, copy it back.
Paste or type your text
Into Your text. The findings appear at once, in the order they occur.
Choose your spelling
US, British, or either kept consistent. The browser underlines unknown words in the box.
Fix the errors
Press Fix on one, or Fix all errors for every error with a single correction.
Decide on the checks
Show in the box selects the words, so you can change them yourself.
Read the style notes
Passive voice, long sentences and wordy phrases are choices, not mistakes.
Copy the text
Copy the text puts the corrected text on your clipboard.
What people check here
Text that has to be right, and text that should not be sent to anyone else to check.
Emails before sending
A work email or an application, checked for the slips that look careless.
Confidential documents
Contracts, HR letters, patient letters and anything else that should not be pasted into an online service.
Schoolwork
Essays and homework, with each rule named so the reason is learnt as well as the fix.
English as a second language
A or an, the past participle after have, and he doesn’t: the rules learners are tested on.
Reports with two spellings
A document written by people in the US and the UK, made consistent.
Posts and reviews
A comment, a review or a listing, checked before it goes public.
Work computers
Machines where browser extensions cannot be installed, but a web page can be used.
Editing drafts
Wordy phrases and long sentences found in a draft before it goes to an editor.
Every rule this grammar checker uses, with an example
Every check this page makes is below, typed into the tool with the result it gave. The free checkers in the search results describe categories, such as grammar, punctuation and clarity, and none of them publishes the rules behind them. Here is the whole list:
| Rule | Kind | Typed in | Found | After Fix |
|---|---|---|---|---|
| Common misspellings | Error | We recieved it untill Friday. | 2 | We received it until Friday. |
| Contractions without the apostrophe | Error | I dont think youre late. | 2 | I don’t think you’re late. |
| A word written twice | Error | It is in the the report. | 1 | It is in the report. |
| A or an | Error | It was a error, an union and a hour. | 3 | It was an error, a union and an hour. |
| Could of, should of, would of | Error | We could of won. You should of asked. | 2 | We could have won. You should have asked. |
| Then for than after more, less, rather | Error | It took more then a week. | 1 | It took more than a week. |
| Your/you’re, its/it’s, their/there | Error | Your welcome. Its a test. Their is time. | 3 | You’re welcome. It’s a test. There is time. |
| Phrases written as they sound | Error | For all intensive purposes, we won. | 1 | For all intents and purposes, we won. |
| He don’t, they was, should have went | Error | He don’t know. They was late. I should have went. | 3 | He doesn’t know. They were late. I should have gone. |
| A lower-case i on its own | Error | You and i know what i’m doing. | 2 | You and I know what I’m doing. |
| A space before a comma, none after it | Error | Hello , world. It works,see? | 2 | Hello, world. It works, see? |
| Doubled commas and full stops | Error | Wait,, what happened.. | 2 | Wait, what happened. |
| A small letter after a full stop | Check | It rained. we stayed in. | 1 | It rained. We stayed in. |
| A bracket or quotation mark left open | Check | Read the notes (see below. | 1 | Listed, no single fix |
| US and UK spelling mixed | Check | The colour matches the color chart. | 1 | The color matches the color chart. |
| Passive voice | Style | The forms were checked by the team. | 1 | Listed, no single fix |
| A sentence over 25 words | Style | When the meeting finally started, the team discussed the budget, the timeline, the new hires, the office move and the plan for next year before anyone had a chance to eat lunch. | 1 | Listed, no single fix |
| Wordy phrases | Style | We met in order to plan. | 1 | We met to plan. |
| Two spaces where one will do | Style | Two · spaces here. | 1 | Two spaces here. |
| !! and ?? | Style | Really!! Are you sure?? | 2 | Really! Are you sure? |
| Fillers (off unless ticked) | Style | It was very good, really. | 2 | Listed, no single fix |
The lists behind the rules. Common misspellings: 163 words, from accomodate to wierd, each with its correction. Contractions written without the apostrophe: 33, such as dont, youre and im; cant, wont, ill and were are left out because each is also a word. Phrases written the way they sound: 39, such as free reign, sneak peak and should of’s cousins per say and mute point. Wordy phrases with a plain replacement: 55. US and UK spelling pairs: 72, with their plurals and verb forms, and 36 verbs that take -ize or -ise.
How the agreement rules stay safe. The checker does not parse sentences, so it only calls an agreement error when the words themselves settle it: he don’t, they was, had went. The forms was checked is wrong too, but deciding that needs to know that forms is the subject, and the checker does not guess. It says so in what it does not catch.
Error, check or style: what each finding means
A finding is not always a mistake, and a checker that calls everything an error teaches people to ignore it. Each finding here is one of three kinds:
| Kind | What it means | Examples | Fix all errors |
|---|---|---|---|
| Error | Wrong wherever it appears, with one correction | could of, a error, the the, recieve | Fixed |
| Check | Usually wrong, with real exceptions, so you decide | had had (correct in she had had enough), a SQL (said as “sequel”), its just, a small letter after etc. | Left; fix each one yourself |
| Style | A choice that is not wrong, which you may want to make differently | Passive voice, a 40-word sentence, in order to, two spaces | Left |
On the screen, errors are underlined, checks have a dotted line and style a dashed one, and each finding in the list is labelled with its kind, so none of it rests on colour. Ignore hides every finding of the same rule on the same words, for this text and the next, until you press Show ignored findings again.
Passive voice is a good example of style. The forms were checked by the team is correct English; it hides or delays who did the checking. That is right when the doer is unknown or beside the point (I was born in May) and weaker when the reader needs to know who acts. The checker finds a form of be followed by a past participle, and leaves the decision with you.
A or an: the sound decides, not the letter
The rule is about sound, not spelling: a before a consonant sound, an before a vowel sound. Merriam-Webster and the Government of Canada’s writing guide put it the same way. Most checkers know the easy half, a word starting with a, e, i, o or u. The hard half is the words where the letter and the sound disagree, and that is where people make the mistake:
| Correct | Why |
|---|---|
| an hour | The h is silent: the word starts with a vowel sound. So do honest, honour and heir. |
| a unit | U said “you” starts with a y sound, a consonant. So do union, user, usual. |
| a one-off | One starts with a w sound. |
| a European | Eu said “you”. |
| an 8-page form | Eight starts with a vowel sound; so do 11, 18 and 80 to 89. |
| an 11-year-old | Eleven starts with a vowel sound. |
| an X-ray | The letter X is said “ex”. |
| a T-shirt | The letter T is said “tee”. |
| an MRI | Read letter by letter, M is said “em”. Listed as a check, not fixed in bulk. |
| a UFO | U is said “you”. Listed as a check. |
Abbreviations depend on how you say them. Read letter by letter, FBI starts with “eff” and takes an; said as a word, NASA starts with “n” and takes a. Some go both ways: SQL is “es-cue-el” to some people and “sequel” to others, and FAQ is said as letters or as “fak”. When an abbreviation could be said as a word, the checker accepts either article; when it can only be read as letters, it lists a mismatch as a check with the fix, but never changes it in bulk.
Accepted either way: a historic and an historic, a hotel and an hotel, and a herb and an herb (American English drops the h). These are differences of accent, not errors, and the checker leaves them alone.
Spelling: your browser’s dictionary and the common misspellings
A spell checker needs a dictionary of every English word and its forms, which is several megabytes. Your browser already has one, so this page uses it instead of loading another:
Unknown words are underlined in the box by your browser, as in any text field. Right-click (or long-press on a phone) an underlined word for its suggestions, or to add it to your dictionary. Chrome, Edge, Firefox and Safari all do this, and choosing US English or British English above tells the browser which dictionary to use where it has both.
Common misspellings are listed with a fix by the checker itself: 163 of the words most often got wrong, such as recieve, seperate, definately and untill. Fix all errors corrects them in one go, which the browser’s underline cannot.
Privacy. Chrome’s basic spell check runs on your device and, in Google’s words, does not send the text you enter to Google. Its Enhanced spell check, an option you turn on in Chrome’s settings, sends what you type in text boxes to Google for better suggestions; Edge has a similar enhanced option of its own. If either is on, the browser sends your text whatever page you are on. This checker itself sends nothing.
What no spell checker catches is a real word in the wrong place: form for from, there for their, loose for lose. The checker finds those only where the next word settles it, as in their is, your welcome and loose weight.
US and UK spelling in one text
Mixing American and British spelling in one text is the error spell checkers miss, because both colour and color are in an English dictionary that has both. Choose how to check it under Spelling:
| Setting | Finds | Example |
|---|---|---|
| US or UK, kept consistent | Both spellings of a word family in one text; the fix is the one you used more often | colour and color → whichever is the majority |
| US English | British forms | centre → center, organise → organize |
| British English | American forms, but not -ize | color → colour, traveled → travelled; organize left alone |
Why -ize is not called American. Oxford spelling, the house style of Oxford University Press and of many international bodies, writes organize and realize in British English, so -ize is not an error in a British text. What the checker does find, with either setting, is -ise and -ize mixed in one text. Analyse and paralyse are British in every style, Oxford’s included, so those are checked.
The 72 word pairs cover the families that differ most: -or/-our (color, honor, neighbor), -er/-re (center, theater, fiber), -ense/-ence (defense, offense), a doubled l (traveled, canceled, labeled), and single words such as gray/grey, aluminum/aluminium and jewelry/jewellery. Words that differ in meaning as well as spelling, such as check and cheque or program and programme, are not in the list.
What this grammar checker does not catch
A checker that does not say what it misses invites you to trust it on everything. This one reads words and their neighbours, not meaning, so:
| It finds | It does not find |
|---|---|
| He don’t, they was, I should have went | Agreement that needs the subject found first: The list of names were long, The forms was checked |
| Their is, your welcome, its a, more then | A real word in the wrong place with nothing to give it away: to for too, form for from, affect for effect in most sentences |
| A space before a comma, none after it, doubled marks | Missing commas, comma splices, run-on sentences, semicolons in the wrong place |
| Passive voice, long sentences, wordy phrases | Whether the sentence is clear, the tone is right, or the argument holds |
| 163 common misspellings, with the browser underlining the rest | Names, technical terms and words your browser’s dictionary does not know, which it underlines even when they are right |
| English | Other languages: the rules are English rules |
The AI checkers in the results can catch more of the right-hand column, because a language model reads whole sentences; they also rewrite more than you asked, and the text has to leave your device. Wikipedia’s article on grammar checkers sums up the long-standing criticism: like spell checkers, they miss real errors and flag correct text. Use this checker to clear the mechanical mistakes fast, then read the text once more yourself, aloud if you can: that is the check nothing replaces.
This checker, Grammarly, GPTZero, Scribens or Word
Free grammar checkers compared on what their own pages say, checked 31 October 2026.
| This checker | Grammarly (free) | GPTZero | Scribens (free) | Word or Google Docs | |
|---|---|---|---|---|---|
| Where the text is checked | In this browser; nothing sent | Online | Online | Online; says nothing is stored | In the app; Docs online |
| Length limit | None set (500,000 characters kept) | Not stated; AI features 100 uses a month | 10,000 characters a check | 8,000 characters a day | None |
| Rules listed | All 21, with examples | Categories only | Categories only | Categories only | Categories only |
| Says what it misses | Yes | No | No | No | No |
| Reads for meaning | No: patterns only | Yes, with AI | Yes, with AI | Yes | Partly |
| US and UK mixing | Found, -ize allowed in British | Dialect setting | Not described | Not described | By document language |
| Sign-up | None | For the full checker | None for the free check | None | Account for Docs |
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Frequently asked questions
How can I check if my sentence is correct?
Paste it into the box at the top of this page. Each finding is listed with its rule and, where there is one correction, a Fix button; your browser underlines unknown words. If nothing is found, read the sentence aloud as well: this checker matches patterns of words and does not judge meaning, so a real word in the wrong place can pass.
How do online grammar checkers work?
In one of two ways. Rule-based checkers, like this one and the older checkers in word processors, match the text against patterns known to be wrong, such as could of or a before a vowel sound. AI checkers send the text to a language model that reads whole sentences and suggests rewrites. The first kind can list its rules; the second cannot, and needs a server.
Is this grammar checker free, and is there a word limit?
It is free with no sign-up, and there is no word or character limit to pay to lift. Up to 500,000 characters are kept in the box between visits, which is a novel. For comparison, GPTZero’s checker takes 10,000 characters at a time and Scribens’ free plan 8,000 characters a day.
Is my text stored or sent to a server?
No. The checking happens in your browser, and the text is kept in this browser’s storage on your device so a reload does not lose it; nothing is sent. One exception is outside this page: if you have turned on Chrome’s Enhanced spell check, or Edge’s, the browser itself sends what you type for spelling suggestions.
Does it check spelling?
In two ways. Your browser’s own spell checker underlines unknown words in the box, with its suggestions on a right-click. The checker adds a list of 163 common misspellings, such as recieve and seperate, and 33 contractions written without the apostrophe, such as dont, which Fix all errors corrects in one go.
Is it a or an before a word that starts with a vowel?
It depends on the sound, not the letter. An goes before a vowel sound and a before a consonant sound, so an hour and an MRI, but a unit, a European and a one-off. Numbers go by how they are said: an 8, an 11, an 18. The checker fixes the clear cases and lists abbreviations as checks.
Is it could of or could have?
Could have. Could of comes from hearing could’ve, which sounds like could of; of is a preposition and cannot follow could. The same goes for should of, would of, must of and might of. The checker marks each as an error and Fix changes of to have.
What can a grammar checker not catch?
Meaning. This one cannot tell whether a sentence says what you meant, whether a real word is the wrong one (form for from), or whether agreement is right when the subject is several words back (the list of names were long). Missing commas, comma splices and tone are also beyond it. The section What this grammar checker does not catch lists them.
Is this a replacement for Grammarly?
No. Grammarly and the other AI checkers read whole sentences and catch more, at the cost of sending your text to their servers. This checker is for the mechanical mistakes, checked privately and with every rule named, which suits confidential text and machines where extensions are not allowed. Many people use both.
Does it check British English?
Yes. Choose British English under Spelling and American forms such as color and traveled are listed with the British spelling as the fix. Words ending in -ize are left alone, because Oxford spelling uses -ize in British English; -ise and -ize mixed in one text are found with any setting.
Related guides
Longer answers to the questions behind the numbers.
- Counting
Why word counts differ between tools
The same sentence is 26 words to one counter and 39 to another. Four counting rules side by side, and how to meet a hard limit whichever one a form uses.
- Reference
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Synchronous vs asynchronous, mod-N, ring and Johnson, industrial and PLC counters, plus mechanical and software counters.