How to check grammar and spelling
- Paste or type your text: an email, essay, cover letter, report, blog post or social media caption.
- Choose US, UK, Canadian, Australian or Indian English, then press Check my text. The first check downloads the grammar engine once; after that checks take a fraction of a second.
- Problems are underlined: red for spelling, blue for grammar and word choice, orange for punctuation and style. Each one is explained in the list.
- Press a suggestion to fix it, Ignore to dismiss it, or Accept all first suggestions to fix everything at once. The text is re-checked as you type.
- Copy your corrected text when you are done.
A grammar checker that keeps your writing private
Most online grammar checkers send everything you type to their servers, which is a problem for confidential emails, contracts, medical notes, student work and unpublished writing. This checker uses Harper, an open-source grammar engine from Automattic, compiled to WebAssembly so it runs entirely inside your browser. Your text never leaves your device, there is no account or word limit, and once the engine has downloaded it even works offline.
It catches common spelling mistakes, confused words (their, there and they're; your and you're; its and it's), wrong articles (a or an), subject–verb agreement, missing capitals, repeated words, doubled spaces and spaces before punctuation, plus many style rules. Like every automatic checker it can miss errors or flag correct sentences, especially names, technical terms and creative writing, so read the suggestions rather than accepting them blindly. It checks English only.
Is my text uploaded or stored?
No. The grammar engine runs in your browser. Only the engine itself is downloaded from a public CDN; your text stays on your device (saved locally so you do not lose it on reload).
Is this grammar checker free?
Yes, with no sign-up and no word limit.
Does it support British English?
Yes. Choose UK, Canadian, Australian or Indian English to use those spellings, such as "colour" and "organise".
Why is the first check slow?
The engine (about 16 MB) is downloaded the first time and then cached by your browser, so later checks are almost instant.