CopyCat

Your clipboard is being watched. Every time you copy text, websites silently log that event — tracking what you highlighted, when you copied it, and whether you pasted it into an AI tool. CopyCat detects and blocks this in real time. FEATURES 🛡 Shield Mode Blocks websites from registering copy, paste, select, and drag event listeners entirely. They simply can't intercept what you copy. 🔖 Invisible Watermarking Embeds a cryptographic HMAC-SHA256 signature into copied text using zero-width characters. If your writing shows up somewhere else, you'll know exactly where it came from. 🔒 Secure Copy (AES-256-GCM Encryption) Encrypts clipboard contents so only CopyCat-enabled tabs can read what you copy. OS clipboard tools and other apps see encrypted garbage. ⏱ Auto-Clear Clipboard Automatically wipes your clipboard after a configurable timeout so sensitive text doesn't linger. 📸 Screenshot Detection Detects PrintScreen key presses and Snipping Tool activity on any page you visit. 🤖 AI Paste Detection Detects when your copied content is pasted into ChatGPT, Claude, Gemini, Perplexity, and other AI tools — and flags watermarked content. 📊 Encrypted Activity Log Keeps a local log of every surveillance attempt, copy event, and AI paste — stored with AES-256-GCM encryption. Nothing is ever sent to a server. PRIVACY FIRST Everything stays on your device. No accounts. No servers. No telemetry. The encryption key never leaves your browser. NOTE: Chrome extensions do not run on Chrome for Android or iOS. CopyCat works on desktop Chrome, Edge, Brave, and other Chromium-based browsers.