hidef — hide & define

Hides confidential details from ChatGPT, Claude, and Gemini before you send. Everything runs on your device.

Hides names, emails, and business details from ChatGPT, Claude, and Gemini before you send — restored locally after. hidef protects what you type into ChatGPT, Claude, and Gemini — before it ever leaves your browser. As you type, hidef quietly checks your message for things like names, emails, phone numbers, ID numbers, and company-confidential details. If it finds any, a review sheet shows you exactly what it caught before your message sends, so you decide what stays hidden and what's fine to share. Nothing sends until you say so. When the reply comes back, hidef restores the real names and details locally in your browser — the AI never saw them, but you still get a complete, readable answer. WHY IT'S DIFFERENT • Everything happens on your own computer. The extension only ever talks to a small companion program (hidef) running on your machine — never to any server we operate. We couldn't see your data if we wanted to. • No account, no sign-up, no telemetry, no analytics. • Open source and auditable — the code, the detection rules, and the security write-up are all public on GitHub. • Works on chatgpt.com, claude.ai, and gemini.google.com. BEFORE YOU INSTALL This extension needs the free hidef companion program running on your computer to work — it's the part that actually recognizes sensitive details and remembers how to restore them. Setup takes about five minutes; instructions are in the extension's popup and at the GitHub link above. This extension is under active development. Bug reports and feedback are welcome on GitHub.