Grammar Checker

Scan your text for common grammar, punctuation, and word-choice mistakes. The checker looks for repeated words, spacing issues, capitalization errors, and commonly confused words like "their/there" — all processed locally in your browser.

Your Text

How was this tool?

Your feedback helps us improve Grammar Checker.

Why use Grammar Checker?

This grammar checker uses a set of pattern-matching rules rather than a language model, which means it is fast, runs fully offline once loaded, and never sends your text anywhere. It focuses on error types that can be detected reliably: double spacing, repeated words, punctuation spacing, missing capitalization at the start of a sentence, and a curated list of commonly confused word pairs. Because it's rule-based, it will not catch every grammatical error a human editor or full AI model would — but it also produces very few false positives, and every flagged issue includes the exact snippet of text so you can quickly judge whether it applies.

Key benefits

Catches repeated words, double spacing, and punctuation spacing errors
Flags commonly confused words (their/there, its/it’s, then/than, and more)
Highlights likely passive-voice sentences as a style note
Runs entirely in your browser — no text is uploaded to a server
No signup, no word limit, no daily cap

Features

Rule-based checks for spacing, punctuation, capitalization, and repeated words
Commonly-confused-word detection with a "double-check this" style note
Passive voice heuristic flagged as a style suggestion, not an error
Each issue shown with an in-context snippet of your text

Popular use cases

Proofreading emails, essays, or blog posts before sending
A quick pass before running text through a full plagiarism or citation check
Catching typos and spacing mistakes missed while typing quickly
Reviewing commonly confused words in a first draft

How to use Grammar Checker

1
Paste your text
Paste or type the text you want checked into the box.
2
Click Check Grammar
The checker scans your text and lists any issues it finds below.
3
Review each issue
Read the message and highlighted snippet for each issue, then edit your original text as needed.

Frequently asked questions

Does this catch every grammar mistake?

No. This is a rule-based checker built around well-defined, low-false-positive patterns — spacing, punctuation, repeated words, capitalization, and commonly confused words. It is not a full AI grammar model and will miss more subtle grammatical errors.

Is my text uploaded to a server?

No. All checking happens locally in your browser using JavaScript pattern matching. Your text is never sent anywhere.

What does a "style" note mean, versus an "issue"?

Style notes (like a possible passive-voice sentence or a commonly confused word) are suggestions to double-check, not confirmed errors — the checker cannot always tell from context whether the word or phrasing is actually wrong.

Why was a correct word flagged as a commonly confused word?

The tool flags words that are frequently misused (like "their") whenever they appear, since it can't fully judge sentence context. If you used it correctly, you can safely ignore that note.

Is there a word limit?

No hard limit, though very long text takes slightly longer to scan since checking happens in your browser.

Last reviewed: July 2026

How was this tool?

Related tools