Fact Sentinel

Protect yourself from misinformation. Auto-detects false claims as you browse + instant verification on demand.

Multiple independent AIs check every claim. You get the verdict in seconds. FactSentinel is an AI fact checker that verifies claims with BOTH OpenAI's GPT models and Anthropic's Claude, then shows you where they agree. One model can be wrong. Two models agreeing, with sources, is how you know. TRY IT IN 10 SECONDS - NO SIGNUP Install, highlight any text, right-click, and choose "Fact Check with FactSentinel" (or press Ctrl+Shift+F). You get 3 free checks instantly, no account needed. AUTO-PROTECTION: FACT-CHECKING THAT WORKS WHILE YOU BROWSE Turn on Auto-Protection and FactSentinel silently scans articles and posts as you read. When it detects a false claim, you get a quiet alert with the verdict, confidence score, and sources. No copying, no pasting, no switching tabs. KEY FEATURES - Multi frontier AI model verification cross-check every claim - Web-search grounding: verdicts on current events cite live sources - Auto-Protection: automatic background scanning on news and social sites - Instant manual checks: right-click any text or press Ctrl+Shift+F - Verdicts with confidence scores: True, False, Partially True, or Unverifiable, never just a thumbs up or down - Correct This on X: reply to misinformation with a sourced correction in two clicks - Protection stats: see pages scanned, claims verified, and false claims caught WHO USES FACTSENTINEL - Readers who want a second opinion before sharing a story - Journalists and researchers verifying claims on deadline - Teachers and students building media literacy - Anyone tired of arguing about what is true without receipts PRICING (start free, upgrade only if you need more) - Guest: 3 free checks, no account - Free account: 10 checks + 50 automatic page scans every month - Platform ($10/month): 100 checks + 400 automatic scans, premium AI models, we handle everything - BYOK License ($29 one time): unlimited checking with your own OpenAI or Anthropic API keys PRIVACY FIRST - Your browsing history stays on your device - BYOK mode: your API keys are stored locally and never sent to our servers; your queries go directly to OpenAI and Anthropic - No selling of personal data, ever SUPPORT Questions or bug reports: support@factsentinel.com Website and web demo: https://factsentinel.com Stop wondering if that viral post is true. Install FactSentinel and know in seconds.