Free Grammar Checker
Paste a draft and the checker lists every mechanical slip it can recognise with certainty — repeated words, a/an mismatches, stray spaces before punctuation, “should of”, then/than, a lowercase “i” — each with the text it found and a fix you can copy. It is a fixed set of rules, not AI, so it is fast, repeatable and private, and it says plainly what it cannot judge. Free, no sign-up.
How to Use the Grammar Checker
- Paste your text. A paragraph or a whole paper works; the results update as you type and nothing is uploaded. Try a sample loads a short paragraph with mistakes in it.
- Read the count. The line above the findings gives the number of likely issues and the word count. If it says none were found, that means no rule matched — not that the draft is flawless.
- Work through the cards. Each finding shows a title, a short reason, the exact text it matched and, where a safe replacement exists, a suggestion with a Copy fix button. “High confidence” findings are almost always real; “Worth a look” ones depend on context.
- Edit your own text. The checker never changes what you pasted. Fix each item in your editor, then paste again to confirm the card is gone.
What the Grammar Checker Looks For
Each rule is deliberately narrow: a miss is cheaper than telling you to “fix” something that was right.
| Rule | Catches | Suggests |
|---|---|---|
| Repeated word | the the, of of (not had had, that that, can can, do do, so so) | the |
| a / an | a interesting, an dataset | an interesting, a dataset |
| Punctuation spacing | a space before , . ; : ! ?, a comma with no space after it, doubled punctuation (!!, ,,), two spaces between words | Remove the extra mark or space |
| Modal + “of” | should of, could of, would of, must of, might of | should have |
| then / than | more then, less then, better then, rather then | more than |
| its / it’s | its a, its an, its been | it’s a |
| Capitalization | a lowercase “i” on its own; a lowercase word right after a period, question mark or exclamation mark (the first word of your text is not checked) | I; the word with a capital |
| Misspellings | 40 frequent errors such as definately, seperate, recieve, occured | The standard spelling |
The a/an rule goes by the sound of the next word, not its first letter, so a university, a one-page summary and an hour are left alone. Abbreviations and capitalised words (an MRI) are skipped for the same reason.
What It Does Not Catch
There is no parser behind this page, so it cannot see grammar that depends on the structure of the sentence. Subject–verb agreement (the results was), tense shifts, dangling modifiers, missing words, fragments, run-ons and wrong prepositions all pass through untouched. The a/an rule works from the first letter and a short list of exceptions, so an university and a hour slip by, and it has no idea whether their should have been there. Treat a clean result as “none of these specific slips”, then read the draft once more yourself.
Worked Example
The sample paragraph has 33 words and the checker reports 9 findings. Two real errors are not among them, which shows the limits:
Draft
Yesterday i finished the the first draft. The results was a interesting finding ,and we should of expected it. This matters alot — more then we thought. it was definately worth the effort.
Found (9)
i → I; the the → the; a interesting → an interesting; “g ,” (space before the comma); should of → should have; alot → a lot; more then → more than; it → It (sentence start); definately → definitely
Missed
The results was should be were, and finding ,and also needs a space after the comma — the checker flags the space before the comma but not the missing space after it.
Which Tool Do You Need?
| If you want to… | Use |
|---|---|
| Scan for the most common mechanical slips in one pass | This Grammar Checker |
| Find every word that is not in a dictionary, with ranked suggestions and a US/UK choice | Spell Checker |
| Review every their/there, affect/effect or accept/except in context, with the rule for each pair | Commonly Confused Words Checker |
| Fix sentence starts, “I”, days, months and proper nouns one click at a time | Capitalization Checker |
There is some overlap on purpose — this page spots its a, more then and a lowercase “i” so you catch them in a single pass — but each sibling goes much deeper on its own job.
Frequently Asked Questions
- Is this grammar checker free, and is my text uploaded?
- It is free, with no sign-up and no word limit. The check runs entirely in your browser, so the text you paste is never sent to a server or stored.
- How is a rule-based grammar checker different from an AI one?
- It applies a fixed list of patterns, so the same text always gives the same result and it can never rewrite a sentence into something you did not mean. The trade-off is range: it catches mechanical slips, not tone, structure or most agreement errors. Many universities restrict AI rewriting tools, and this page only points at problems — it never edits your text.
- Why did it miss an obvious mistake?
- Because the mistake needed grammar knowledge the rules do not have. Subject–verb agreement, tense, fragments, run-ons and missing words depend on how the whole sentence is built, and a pattern match cannot see that. Read the draft aloud, or have someone else read it, to catch those.
- What is the difference between “High confidence” and “Worth a look”?
- High-confidence findings come from rules that are almost never wrong in prose, such as a repeated word or should of. “Worth a look” marks rules that depend on context — the a/an check, its a, and a sentence that begins with a lowercase word — where a quotation, a code term or a name could be the exception.
- Should I write “should have” or “should of”?
- Write should have. The spoken contraction should’ve sounds like “should of”, which is why the error is so common, but of is never part of the verb. The same applies to could have, would have, must have and might have.
- Does a clean result mean my essay has no errors?
- No. It means none of the specific patterns above appeared. Check spelling with the Spell Checker, review confusable words with the Commonly Confused Words Checker, and have a person read for sense and structure.
- Does it check my citations?
- No. This tool only looks at prose. To check a reference list use the APA Citation Checker or the MLA Citation Checker.