// open source · bring your own api key · no subscription
The grammar tool that
actually teaches.
A small, free Chrome extension for non-native English speakers. It reads your text, shows you what to fix, and explains why — like a colleague leaving comments on a pull request.
$ npm install nothing · sign up nowhere · use today
Write where you already write.
Gmail, Slack, GitHub, Notion, your CMS, that one ancient internal tool — anywhere there's a text field.
Hit one shortcut.
⌘ ⇧ K on Mac, Ctrl ⇧ K on Windows. Nothing runs until you ask.
Read the diff. Read the rule.
Each correction comes with a one-sentence explanation. Accept, skip, or argue with it.
Every fix comes with a reason — that's the whole point.
Other tools tell you what's wrong. writerIAit tells you why, in plain language, in one line.
Your text · in Gmail
Hi Sarah, I wanted to follow up in the email I sended last week about the proposal. Please let me know if you have any question. I am available for discuss anytime this week.
"Send" is irregular. Past tense is "sent", not "sended".
After "any" in questions and negatives, use the plural.
"Available" takes a to-infinitive — common ES/PT transfer error.
// open source
It's everybody's tool.
writerIAit is MIT licensed and lives entirely on GitHub. There's no company behind it, no roadmap behind a paywall, no analytics watching you type. The repo is the product.
If something's broken, open an issue. If you want it to do something it doesn't, open a pull request. If you wish the explanations were in your language, fork it and translate them — the whole point is that anyone writing in their second language can shape the tool that helps them learn.
#1 Use it freely
Personal projects, work, side projects, in a classroom, in a startup — wherever. No license fee, no attribution required, no quotas.
PR Change anything
Don't like a UI choice? Want a new provider? Disagree with how a rule is explained? Open a pull request. The community owns the direction.
fork Or fork it
Spin up your own version with your own rules, your own provider list, your own brand. The MIT license is short for a reason.
∅ Trust nothing
No backend exists. Your text goes from your browser straight to the LLM you picked. Read the source code yourself — that's the only audit that matters.
Bring your own key · two free tiers, two paid
gemini-2.0-flash-lite
Google AI Studio key. Generous free limits.
llama-3.1-8b-instant
Free tier, near-instant inference.
gpt-4o-mini
Higher quality. Fractions of a cent per check.
claude-haiku-4-5
Best on tricky grammar. Cost-efficient.