CopyCat

Know when websites spy on your clipboard. Block tracking, watermark your writing, and detect when it's pasted into AI.

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.