Fact Sentinel

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

FactSentinel is an AI-powered fact-checking tool that helps you identify misinformation in real time. HOW IT WORKS Passive Monitoring — FactSentinel automatically scans pages as you browse, detecting false or misleading claims on news sites, social media, blogs, and forums. When something questionable is found, you get a notification with a verdict, explanation, confidence score, and sources. Manual Fact-Checking — Highlight any text on any webpage, right-click, and select "Fact Check with FactSentinel" to get an instant AI-powered verification. You can also use the keyboard shortcut Ctrl+Shift+F (Cmd+Shift+F on Mac). Correct Misinformation on X/Twitter — When false claims are detected on X.com, use the "Correct This" button to compose and post a correction reply directly from the notification. Choose from three reply formats: verdict + explanation, verdict + sources, or a full thread. FEATURES - Real-time passive monitoring across news, social media, blogs, and forums - Manual fact-checking via right-click context menu or keyboard shortcut - AI-generated verdicts with confidence scores and source citations - Web search-enhanced verification for up-to-date accuracy - Smart notifications that adapt to your usage (full details, brief alerts, or badge-only) - One-click corrections on X/Twitter with pre-composed replies - Verification history so you can revisit past checks - Works with multiple AI providers (OpenAI, Anthropic) TWO WAYS TO USE IT Platform Mode — Create a free account at factsentinel.com and start fact-checking immediately. No API keys needed. Free tier includes limited monthly checks with options to upgrade. Bring Your Own Keys — Use your own OpenAI or Anthropic API key for unlimited fact-checking. Your queries stay completely private and are never logged. You pay API costs directly (typically $0.01-0.05 per check). PRIVACY FactSentinel respects your privacy. In BYOK mode, your queries are sent directly to your chosen AI provider and are never stored. In Platform mode, queries are processed through our API with standard privacy protections. No browsing data is collected or sold. GETTING STARTED 1. Install the extension 2. Choose Platform mode (free account) or Bring Your Own Keys mode 3. Browse normally — passive monitoring works automatically 4. Right-click any text to manually fact-check Learn more at factsentinel.com