Proofly
Private AI proofreading that runs 100% on your device
150 followers
Private AI proofreading that runs 100% on your device
150 followers
Proofly is a free, open-source Chrome extension that gives you industry-class proofreading without sending a single word to the cloud. Powered by Chrome’s built-in on-device AI, it underlines issues as you type and fixes spelling, grammar, punctuation and more – all locally. No accounts, no tracking, works offline, and a lightweight, non-invasive UI that respects your page, your focus and your privacy.
Proofly
Hey Product Hunt 👋 I’m Önder, the maker of Proofly.
For years I loved how tools like Grammarly and LanguageTool make writing easier, but I never felt fully comfortable sending every email, doc, and DM to someone else’s servers - especially for sensitive work, legal stuff, or private conversations. On top of that, most extensions inject heavy scripts and UI that slow pages down and clutter the host interface.
Proofly is my attempt at a different path: a privacy-first, open-source writing assistant that lives entirely in your browser and runs on Chrome’s built-in on-device AI (Gemini Nano). Your text never leaves your machine, it works offline after the initial model download, and there’s no account, no telemetry, no tracking as you can verify in the code.
Under the hood, Proofly uses native and modern Web Tech without relying on bloated frameworks and dependencies: Web Components, Shadow DOM, CSS Highlights, and a custom overlay system to paint precise underlines without mutating the page DOM. That keeps the footprint tiny, avoids layout bugs, and ensures the host site stays fully in control while Proofly just “floats” on top. It supports inputs, textareas, and contenteditable fields by respecting web semantics with the same lightweight UX, plus a side panel for power users who like to navigate through issues and triage them in bulk. The user experience of getting a proofreading assistance and fixing the issues are revamped with a fresh look at the problems. Watch the introduction video to see some of the amazing features and fresh ideas that Proofly introduces.
This launch is our first public alpha, focused on people who care about both writing quality and privacy: developers, founders, lawyers, journalists, therapists, and anyone who writes sensitive stuff in the browser. You’ll see "spelling", "grammar", "punctuation", "capitalization", "preposition", and “missing word” issues highlighted, with on-point inline suggestions instead of overly chatty AI.
I’d love your help with three things:
1. Tell me where privacy around writing matters most in your workflow (Emails, instant messages, helpdesk, CRM, docs, etc.).
2. Compare the suggestions to your current grammar checking tool - are they accurate and fast enough for real use?
3. Share what local AI writing assistance you’d want next (rewrites, tone shifts, templates, etc.) so we can shape the roadmap.
If you believe people shouldn’t have to trade privacy for good writing assistance, an upvote, comment, or share would mean a lot and help Proofly reach more writers. And if you’re into open source, you’re very welcome to star the repo, open issues, or jump into discussions on GitHub - links are in the launch sidebar.
Thanks for checking Proofly out 🙏
My b2b company allows only white-listed extensions and Grammarly is not one of them. Big chances I can get this one through and write better emails.
Proofly
@mary_grigoryeva Thanks a lot for your support! It could be indeed a valid use case for companies with privacy concerns.
Loved the idea. You are making this a better place with this small step.
22GB is a bit too much for just one use case.
Maybe if the model is skimmed to basic requirements it takes lesser space and processing power.
Proofly
@somangshu Agreed with the size concern. The model Chrome downloads, is used for enabling other AI APIs too: https://developer.chrome.com/docs/ai. Many of those APIs depend on this model, which requires a one-time download action from any apps or extensions using them.
How's it better then Gammarly?
Proofly
@pasha_tseluyko please tell me what you think.
One big difference is being privacy-focused. Proofly doesn’t need your data. And, by design it relies on a local AI model to check for writing problems, this enables offline use. These two important use cases are missing in Grammarly.
In addition, there are new user friendly UI patterns and customization options that Proofly introduces. The UX is built from the ground up to make interruptions and distractions on the page minimal.
Quaterion
Finally a writing assistant I can actually use. Congrats on the launch!
Proofly
@monatis thanks a lot for your support!
Congratulations on the launch! And can I set up automatic translation of what I write? Sometimes I need to translate into Spanish, which I don’t know. I have to copy from ChatGPT every time and paste it into the necessary browser windows. I’ve been thinking for a long time about an app that would free me from this useless activity.
Proofly
@mykyta_semenov_ thanks for sharing your use case. Proofly focuses on proofreading use case for now and does not help with translation use cases. However, there will be another launch soon which might help with your use case.
Vocably (a language-learning tool)
Awesome! This is something the world needs!
Proofly
@sneas Thank you so much for your support!