AI typo and grammar fixer
Fix spelling, grammar and punctuation mistakes — Chinese 的/地/得 errors included — without rewriting anything else.
Your key stays in your browser.It goes straight to the provider, never to our servers, and we neither log nor keep it. Use a dedicated key with a spending cap, and delete it in the provider's dashboard when you are done.
Input
Result
The result will appear here.A proofreader that corrects mistakes and nothing more. Misspellings, confused homophones (their/there, its/it's), missing or doubled words, wrong punctuation and unbalanced brackets get fixed; sentences that are already correct come back exactly as you wrote them. It handles Chinese too: 的/地/得 and 在/再 mix-ups, other wrong characters, and half-width commas in Chinese prose — without converting between Simplified and Traditional. The prompt is Fabric's fix_typos pattern with much tighter limits on what the model may change.
How it works
- The model is told not to rephrase, reorder or restyle, so the corrected text differs from yours only where there was an error.
- British or American spelling, Simplified or Traditional characters: whichever convention the text already uses is kept, not normalised.
- Code, URLs, file paths, names and Markdown are left as written, which makes it safe to run on READMEs and CONTRIBUTING files.
- Text without errors comes back unchanged — a quick way to confirm a paragraph is clean before you send it.
Where your data goes
With your own key, what you type and the key go from your browser straight to the provider you choose; neither passes through Hysen Labs. In hosted mode, your text goes through our server to our provider (DeepSeek) and is billed in credits; we keep the token counts and cost of each run for billing, never the text itself or the answer. How the provider handles the text is governed by its own privacy policy.
This tool handles keys and credentials, so nothing about a run is saved, not even to your own history.
About your API key
We do not collect, store or leak your key: it lives only in this page's memory (unless you tick “remember in this tab”) and is gone when you close it. Still, treat any key you have pasted into a web page with care — create a dedicated key with a spending cap for use here, and delete or rotate it in your provider's dashboard when you are done.
What it costs
This tool is free, with no sign-in and no points.
Common questions
- How do I see what was changed?
- The output is only the corrected text, so it can be pasted straight back. To review the fixes, put the original and the corrected version into the diff checker with word-level comparison; every correction shows up as a highlighted change.
- Does it catch errors a spell checker misses?
- Yes, that is the point of it. A dictionary spell checker cannot tell that "your changing the API" should be "you're", or that 的 should be 地 before a verb, because every word is a real word. A language model reads the sentence and catches those. It can still miss one or, rarely, "fix" a deliberate spelling, so read the result.
- Where does my text go?
- From your browser straight to the AI provider you pick, authenticated with your own key — it never passes through our server. Proofreading uses very few tokens, so a key created for this purpose with a small spending cap is plenty; delete it when you are finished.
The open-source behind it
This tool's prompt is adapted from danielmiessler/Fabric (MIT) and runs on the model you choose. To use the same capability from the command line or inside your own program, start with that project.
danielmiessler/FabricAlso known as
- typo checker
- spelling and grammar check
- fix typos online
- proofread text
- chinese typo checker
- punctuation checker