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.
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.
Impressive launch, Proofly team. From a clarity & onboarding lens: when a user installs Proofly for the first time, what’s the one belief you want them to hold in the first 10-15 seconds? Is it: • “My writing is corrected without ever leaving my device.” Or: • “This tool respects my privacy and still improves my writing.” Because in writing tools the biggest adoption barrier isn’t more features; it’s the user instantly believing this works and it’s safe. Curious how you’re shaping that moment.
Interesting concept. You said this is open-source, can you share the codebase link?
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.
About Proofly on Product Hunt
“Private AI proofreading that runs 100% on your device”
Proofly launched on Product Hunt on December 6th, 2025 and earned 132 upvotes and 15 comments, placing #6 on the daily leaderboard. 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 was featured in Chrome Extensions (52.6k followers), Writing (59.1k followers), Artificial Intelligence (466.2k followers) and GitHub (41.2k followers) on Product Hunt. Together, these topics include over 128.4k products, making this a competitive space to launch in.
Who hunted Proofly ?
Proofly was hunted by Önder Ceylan. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how Proofly stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Önder Ceylan
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 🙏