AI Grammar & Spelling Fixer at a glance
- What it does
- Correct grammar, spelling and punctuation using your own AI API key, with an explanation of what automated checking catches and what it misses.
- Where it runs
- In your browser, plus one request to the AI provider you configured
- Works offline
- No — it needs a live service to answer
- Cost
- Free, with no account and no usage limit
- Category
- AI Tools
How to use the grammar fixer
- Set up your API key once in the settings panel.
- Paste your text.
- Review the corrected version against your original before accepting it.
You bring your own API key. There is no subscription and no hidden quota here. Your key is stored in this browser's local storage and the request goes directly from your browser to the provider you chose — OpenAI, Anthropic or Google. Our servers are not in the path and never see the key or your text. Usage is billed to your own account by that provider, at their rates.
What it reliably catches
- Typos and misspellings, including real-word errors like "form" for "from" that a spellchecker misses because both are words.
- Subject-verb agreement, especially across long clauses where the subject is far from the verb.
- Tense inconsistency within a paragraph.
- Article errors - a persistent difficulty for speakers of languages without articles, and one automated checking handles well.
- Punctuation: comma splices, missing serial commas, misplaced apostrophes.
- Preposition choice, which is largely idiomatic and hard to learn from rules.
What it misses or gets wrong
Deliberate style. Fragments used for emphasis, sentences beginning with "And", a conversational register - these get corrected into flatness. If your writing has a voice, review each change rather than accepting all.
Domain terminology. Technical terms, product names and field-specific usage get "corrected" into ordinary words. This is the most common damage.
Regional conventions. British and American spelling, punctuation inside or outside quotation marks, date formats. Say which variety you want.
Factual and logical problems. A grammatically perfect sentence can still be wrong, contradict the previous paragraph, or fail to say what you meant. Grammar checking does not read for sense.
Structure. The paragraph in the wrong place, the argument that does not follow, the missing explanation. These are the problems that matter most and no checker addresses them.
If English is not your first language
This is where automated correction is most valuable, and the advice is to use it actively rather than passively.
Look at each change and work out why it was made. Article usage, preposition choice and countable versus uncountable nouns are the three areas that produce the most corrections, and they are all learnable from repeated examples. Correcting the same category of error fifty times teaches the pattern in a way a grammar book rarely does.
Accepting corrections without reading them fixes the document and teaches you nothing.
Where it belongs in a workflow
Last. Grammar checking is a finishing pass, and running it on an early draft wastes effort on sentences you are about to cut.
The order that works: write the draft, fix the structure, cut what does not earn its place, then check the grammar. Reading the final version aloud catches things no checker does - the sentence that runs out of breath, the repeated word, the clause that turns out to say nothing.
Frequently asked questions
It catches more, including real-word errors and agreement problems that a dictionary-based checker cannot see. It is also more likely to change things you meant, so review rather than accepting wholesale.
It tends to. Models normalise toward a neutral register, so deliberate fragments and conversational phrasing often get corrected. Compare against your original and keep what you meant.
Yes, if you say which you want. Without instruction it may mix conventions, which is more noticeable than either alone.
It is sent to the AI provider you chose, directly from your browser under your own key. We never receive it. Their privacy policy applies to what they do with it.
What this tool sends, and what it does not
Most OmniTool utilities make no network request at all. This one is an exception, and it is worth being precise about it: to do its job, this tool contacts the AI provider you configured, using your own API key. That request goes directly from your browser to that service — we do not proxy it, and we never receive a copy of it or of the response.
Nothing else on this page is transmitted, and we keep no record of what you looked up. The privacy policy lists every tool on the site that makes an outside request, along with what our advertising partner collects.