Fact Sentinel: AI Fact Checker

FactSentinel is an AI fact checker for your browser. Verify any claim in seconds, or let automatic misinformation detection flag false claims on news articles and social media as you browse. HOW IT WORKS - Select text on any page, right-click, and choose "Fact Check with FactSentinel" (or press Ctrl+Shift+F / Cmd+Shift+F) - Get a verdict, a confidence score, and a sourced explanation - Manual checks are cross-checked by two AI models (OpenAI GPT and Anthropic Claude), so one model's mistake doesn't become your misinformation AUTOMATIC MISINFORMATION DETECTION Passive monitoring quietly scans articles and social posts for checkable claims and alerts you when something looks false, with smart notification limits so it never gets noisy. TRY IT FREE, NO SIGNUP - 3 free fact-checks as a guest, no account needed - Free account: 10 manual checks and 50 automatic scans per month - $10/month Platform subscription: 100 manual checks and 400 automatic scans per month on our managed AI - $29 one-time lifetime license: unlimited checks with your own OpenAI or Anthropic API key PRIVACY We don't keep your claims. Text you check is sent to our AI providers to get a verdict and is never saved to our database or logs. We keep only an anonymous fingerprint and the result, cached for at most 24 hours. With your own API keys, your text never reaches our servers. Works everywhere you read online. Get a second opinion before you share.