Spiimask is a free, local Chrome extension that masks your sensitive data — IDs, emails, phones, cards, secrets — before it ever leaves your browser for ChatGPT, Claude, or Gemini.
Tap a card for details
No cloud accounts, no API keys, no complex setup. Just add to Chrome and type normally.
The masking happens directly on your machine. Your unmasked data never touches our servers.
You don't have to change how you work. Spiimask runs silently in the background of ChatGPT, Claude, and Gemini.
Tap a card for an example
Email, mobile & landline, international phone.
Israeli ID, passport, US SSN, UK NI.
Credit cards, IBAN, SWIFT/BIC, company & VAT, CVV, expiry.
Passwords & API keys for 55+ services.
Ethereum and Bitcoin addresses.
IPv4, IPv6, and MAC addresses.
Health-fund member numbers.
Define custom patterns that always get masked.
Titled names and street addresses — Beta.
New patterns added regularly.
Spiimask only masks what it's sure about — so your prompts keep working.
Credit cards, IBAN, and Israeli ID & company numbers are verified before masking. A number that fails its checksum is left untouched.
Ambiguous values are masked only when their label is right next to them. A random number or word is never touched.
Click “Install Free Extension” to open the Chrome Web Store, add it to Chrome, then refresh your AI tab.
Chrome, for now — more browsers are coming soon.
ChatGPT, Claude, and Gemini.
After installing, refresh the AI tab (F5). Extensions don't load into tabs that were already open before you installed.
100% local — your unmasked data never leaves your browser. No account, no tracking.
Spiimask catches the most common sensitive data — but no tool catches everything, and we'd rather be upfront.
Yes! Click the extension icon and scroll down. You'll find 5 slots to add your specific address and custom names/terms you want hidden.
Contact us and we'll help.