Online Proofreader

Proofread text for spelling, common grammar mistakes, punctuation and wordy style in one pass. Every suggestion names the rule it comes from, so you can accept it or skip it.

Runs in your browser
Free, no sign-up
Unlimited use
Updated 30 September 2026

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Runs in your browser

Checks spelling against a Hunspell US English dictionary plus the grammar, punctuation and style rules listed below. It is rule-based, not AI: it catches common mistakes but can't understand meaning, so read each suggestion before accepting it.

Accept British spellingscolour, organise, centre, travelled, defenceIgnore words in CAPITALSAcronyms such as NASA or API

Show hintsPatterns that are often, but not always, mistakes

After the first check, results update as you edit.

Your text

Press Proofread to start.

Results

Results appear here: each issue with the rule it breaks and a suggested fix you can accept or ignore.

My dictionary (0 words, saved in this browser)

Words you add with “Add to my dictionary” are kept here, on this device only, and are never reported as misspelled.

What this checker looks for (27 rules)

Double spaces: Two or more spaces between words or after punctuation.
Space before punctuation: A space before , . ; : ! or ? (“word ,” → “word,”).
Missing space after punctuation: A letter straight after , ; ! ? or a full stop that ends a word (“end.Next”). Numbers, URLs and abbreviations such as U.S. are skipped.
Space inside brackets(hint): A space after ( or before ) (“( text )”).
Repeated punctuation: Doubled commas, semicolons or colons, two full stops, or !!/?? (fine in chat, not in formal writing).
Capital letter after a sentence ends: A lowercase word after . ! or ?, or at the start of a paragraph. Abbreviations (e.g., etc., Mr.) and ellipses are skipped.
Missing end punctuation(hint): A paragraph of 12 or more words that doesn't end with . ! ? or a closing quote.
Lowercase “i”: The pronoun I written as i (including i'm, i've, i'll, i'd).
Unmatched brackets: An opening ( [ { without a closing one in the same paragraph, or the reverse. Smileys and list markers like 1) are skipped.
Unmatched quotation marks: An odd number of straight double quotes in a paragraph, or curly “ and ” that don't pair up.
Possible comma splice(hint): A comma followed by a pronoun and a verb (“It's late, we should go”), which often joins two sentences that need a full stop, semicolon or conjunction.
“However” joining two sentences(hint): “, however” in the middle of a sentence without a comma after it; when it joins two sentences it needs a semicolon before it.
Comma after an introductory word(hint): A sentence starting with However, Therefore, Moreover, Furthermore, Nevertheless, Consequently, Meanwhile, Unfortunately or Fortunately without a comma after it.
its / it's: “its” before words that need “it is/has” (its a, its been, its not) and “it's own” (should be “its own”).
Apostrophe in a plural(hint): Decades and numbers with 's (1990's → 1990s).
lets / let's: “lets go”, “lets see” and similar suggestions, which need “let's”.
your / you're: “your welcome” (always “you're welcome”); “your going”, “your right” and similar are flagged as hints.
a / an: “a” before a vowel sound or “an” before a consonant sound, judged from spelling with exceptions (an hour, a university, a one-off).
Repeated word: The same word twice in a row (“the the”). “had had” and “that that” are flagged as hints because they can be correct.
could of / should of: could of, should of, would of, must of, might of → have.
than / then: “then” after a comparative (more then, better then, rather then).
there / their: “their is/are/was/were” → “there”.
Subject–verb agreement: he/she/it don't, you/we/they was, he/she/it have (outside questions).
Common word errors: alot → a lot, irregardless → regardless, could care less (hint), less + plural count nouns (hint).
Wordy phrase(hint): Phrases with a shorter equivalent (in order to → to, due to the fact that → because), from the same list as the sentence rewriter.
Passive voice(hint): A form of “be” followed by a past participle (was written, are made). Passive isn't wrong; the hint helps you check who does what.
Long sentence(hint): Sentences longer than 30 words, which are harder to follow.

Rule-based: it catches the specific patterns listed under “What this checker looks for”, not every grammar error.
English only; spelling uses a US dictionary (British spellings optional).

How to use the online proofreader

1Paste your text into Your text, or press Example to see the checks at work.
2Press Proofread. Results appear on the right and update as you edit.
3Filter by Spelling, Grammar, Punctuation or Style; switch to Marked text to see every issue underlined in place.
4Press a suggestion (such as Change to “an”) to apply it, Ignore to skip it, or Fix all spacing for double spaces and spaces before punctuation.

The built-in example

Input

Its been a busy week , and i think the the team did well. We could of finished sooner, the tests took longer then expected. Their is still a hour of work left.In order to finish, we need to utilize every tester.

Output

Its → It's (its / it's)
“ ,” → “,” (space before punctuation)
i → I (lowercase “i”)
the the → the (repeated word)
could of → could have
sooner, the tests… → possible comma splice (hint)
then → than (than / then)
Their is → There is (there / their)
a hour → an hour (a / an)
left.In → left. In (missing space after punctuation)
In order to → To (wordy phrase, hint)

Real output of the rule set. The spelling check found no misspellings in this text: every error here is a real word used wrongly, which only rules can catch.

What the proofreader checks

Four kinds of check run together:

Spelling: every word against the Hunspell US English dictionary (the same check as the spell checker), with suggestions and your personal word list.
Grammar rules: a/an by sound, its/it's, your/you're, lets/let's, could of/should of, then/than after comparisons, their is/are, repeated words, lowercase “i”, and simple agreement errors such as “she don't” and “they was”.
Punctuation: the full rule set of the punctuation checker: spacing, commas, apostrophes, quotes, brackets, capitals and sentence endings.
Style hints: wordy phrases with shorter equivalents, possible passive voice and sentences over 30 words.

The complete list, with what each rule matches, is under What this checker looks for below the tool.

Reading and applying suggestions

Each result shows the rule name, the sentence around the problem with the problem marked, a one-line explanation and one or more fixes. Results labelled Hint are patterns that are often, but not always, wrong: “your right” is an error in “your right about that” but correct in “your right to vote”. Untick Show hints to see only firmer issues. Applying a fix changes your text directly; the list then refreshes. Ignore hides a single result for this session. Nothing is changed without you pressing a button: the proofreader never rewrites your text on its own.

Common grammar issues it flags

You wrote	Suggestion	Why
a hour, an university	an hour, a university	a/an follows the sound, not the letter
its been	it's been	it's = it is / it has
it's own	its own	its = belonging to it
could of	could have	“could've” misheard
better then	better than	than compares, then is time
their is	there is	their = belonging to them
she don't	she doesn't	he/she/it takes doesn't
alot	a lot	two words

It does not judge word choice (affect/effect), tense consistency, dangling modifiers, or whether a sentence makes sense.

Limits of automated proofreading

This is a rule-based checker, not an AI model or a full grammar parser. It can only find the patterns its rules describe, so a clean result means “none of these patterns found”, not “error-free”. Rules are tuned to avoid false alarms, which means some real errors pass. It also can't check facts, names, numbers or tone. No accuracy percentage is given because it would depend entirely on the kind of mistakes in your text.

A checklist for important documents

Run the proofreader and work through spelling and grammar first, then punctuation, then style hints.
Check names, dates, figures and links by hand against the source.
Read the text aloud or with your browser's read-aloud feature; your ear catches missing words that eyes skip.
Check the length with the word counter if there's a limit.
For essays, run the essay checker for readability and structure.
Leave it for an hour, then read it once more from the end, sentence by sentence.

Is my text private?

This tool runs entirely in your browser. Your text is not uploaded to our servers.

Sources

Questions about the online proofreader

How is this different from the spell checker?

The spell checker only finds words that aren't in the dictionary. The proofreader runs the same spelling check plus grammar, punctuation and style rules, so it also catches real words used wrongly, such as “could of” or “a hour”.

Will it rewrite my text?

No. It suggests specific fixes and changes the text only when you press one. For shorter, plainer wording, try the sentence rewriter's phrase list, and review its changes too.

Does it support British English?

Partly. Tick Accept British spellings and words such as colour, organise and centre are accepted by rule. The grammar and punctuation rules apply to both; it doesn't enforce UK or US punctuation style.

Is my text stored?

No. Checking happens in your browser. The text is kept in this tab's session storage so a reload doesn't lose it, and is cleared when you close the tab.

Last updated 30 September 2026Maintained by Premier SEO Services

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