PerfextPerfext
Make Perfect Texts.
A browser extension that improves your writing as you type.
The Grammarly alternative powered by the AI model you choose.
I want to definately ship this feature, and I think it could be better worded.
Set up in three steps
Install the extension
Add Perfext to Chrome. It opens a quick setup page the first time so you're never left guessing what to do next.
Paste your API key
Pick OpenAI or Anthropic and paste a key from your provider. Perfext tests it on the spot, so you know it works before you start.
Start typing anywhere
Open any text field and write. A few seconds after you pause, suggestions appear inline — hover to Accept or Dismiss.
Writes alongside you
Perfext watches the text fields you type in and reviews them a few seconds after you pause — no buttons, no copy-paste.
Color-coded suggestions
Red marks clear mistakes, yellow marks lines that could read better. Everything else stays untouched.
Perfext AI, or your own key
Sign in to use Perfext's own AI, or bring your own OpenAI or Anthropic key — sent encrypted and never stored. That makes Perfext a Grammarly alternative you can run for the cost of your own API usage.
Pricing
Frequently asked questions
Is Perfext a good Grammarly alternative?
Perfext is a lightweight Grammarly alternative for Chrome. It underlines clear mistakes in red and weaker phrasing in yellow directly inside the text field you are writing in, and you accept or dismiss each suggestion inline. The difference is where the corrections come from: instead of one fixed engine, Perfext sends the text to the AI model you pick — OpenAI or Anthropic — so the quality of the suggestions tracks the state of the art.
Is there a free Grammarly alternative?
Yes. Perfext's free tier has no account and no subscription: you bring your own OpenAI or Anthropic API key and pay only your provider's usage, which for everyday writing is typically cents per month. If you would rather not manage a key, the paid Perfext AI plan includes a hosted model.
How is Perfext different from Grammarly?
Perfext is privacy-first and deliberately small. It does not collect your browsing history, does not track the pages you visit and does not read page content outside the field you are actively typing in. Your writing is never used to train AI models or build a profile, and if you bring your own API key it is encrypted in the browser before it leaves your device and is never stored on our servers.
Where does Perfext work?
On any site you open in Chrome. Perfext supports standard textareas, single-line text inputs and contenteditable rich editors, so it works in email clients, social networks, docs, support tools, CMS editors and internal apps without any per-site setup.
Which browsers does Perfext support?
Perfext is a Manifest V3 extension for Chrome and Chromium-based browsers such as Edge, Brave, Arc and Opera. You can install it from the Chrome Web Store or download the packaged build directly from this site.
Does Perfext train AI models on what I write?
No. Text is sent to an AI provider only to generate the suggestions you asked for, it is not retained as a history of what you write, and provider API terms do not permit training on it. Perfext does not sell your data.
How long does Perfext take to set up?
About two minutes. Install the extension, paste an OpenAI or Anthropic API key (Perfext validates it on the spot) or sign in to use Perfext AI, then keep typing — suggestions appear a few seconds after you pause.
Start writing better in two minutes.
Install it, paste in your API key, and keep typing. That's the whole setup.