PrivateProof — On-Device Proofreader & Tone Checker

Proofread, rewrite tone, and shorten your writing with on-device AI. No account, no cloud — your text never leaves your device.

Tired of pasting your private writing into websites just to fix a typo? PrivateProof proofreads and rewrites your text without it ever leaving your device. Why switch from Grammarly? A fraction of the price: Grammarly Pro costs $12–30/month. PrivateProof Pro is $4.99/month — or $29 once, yours forever. Real privacy: Grammarly processes your writing on their servers. PrivateProof runs 100% on-device — your words never leave your browser, period. What it does Proofread — fix grammar, spelling, and punctuation in one click Make formal — turn casual writing into polished, professional text Make casual — loosen up stiff writing for messages and social posts Shorten — cut the fluff from long emails and paragraphs Copy the result, or replace the text right on the page Private by design Runs entirely on your device using Chrome's built-in AI No account, no cloud, no tracking, no analytics Your words never leave your browser — period Pricing Free: 20 fixes per month PrivateProof Pro: unlimited fixes — $4.99/month or $29 one-time Works on any website with a text field: email, docs, social media, forms, and more. Requires Chrome 138 or newer (for on-device AI). Questions? Email privateproofext@gmail.com