MaskPrompt

About

Automatically redacts emails, API keys, credit cards, and other PII from your prompts before they reach ChatGPT, Claude, or Gemini. No data leaves your browser.

MaskPrompt is a privacy-first browser extension that detects and redacts Personally Identifiable Information (PII) from your AI prompts before they are sent. Every redaction happens entirely on your device — no data is ever transmitted to external servers.

What it redacts:
- Email addresses
- Phone numbers
- Credit card numbers
- Social Security numbers
- IP addresses
- API keys (OpenAI, AWS, GitHub, Google, Stripe)

Supported platforms:
- ChatGPT (Free tier)
- Claude (Pro tier)
- Gemini (Pro tier)

Free tier: 15 redactions/day on ChatGPT. Pro unlocks Claude, Gemini, unlimited redactions, and custom regex patterns.

Privacy: All PII detection runs locally in your browser. The extension never reads, stores, or transmits your prompt content. Only anonymous usage counters are synced to enforce quota limits.