Capsulla

Lightweight Data Leak Prevention — protect sensitive data in your browser.

Most data leaks don't happen through sophisticated attacks. They happen when someone pastes a card number into a support ticket, drags a customer spreadsheet into an AI chatbot, or downloads a file they shouldn't have. Capsulla catches it before it leaves your browser — right inside the sites and apps you already use. ⚫ Real-time clipboard protection Capsulla checks what you paste before it lands — credit card numbers, IBANs, SSNs, emails, phone numbers, AWS keys, and private keys are caught automatically. Depending on the rule, Capsulla warns you, blocks the paste entirely, or masks just the sensitive part and lets the rest through. ⚫ Luhn-verified card detection Card-number matches are checked against a Luhn checksum before Capsulla reacts — so a random 16-digit number in a spreadsheet doesn't trigger a false alarm, but a real card number does. ⚫ File upload & download protection Capsulla blocks uploads and downloads by file type — stop an executable from being downloaded, or a spreadsheet from being dragged into the wrong upload field, before it happens. ⚫ Runs entirely in your browser What you paste, upload, or download is checked locally, the moment you act. The content itself never leaves your device — Capsulla doesn't send it anywhere, ever. ⚫ Custom rules, your patterns The built-in rules cover the common cases, but you're not limited to them. Add your own regex patterns, choose whether Capsulla should warn, block, or mask, and tune it to what your work actually involves. ⚫ Trusted domains Whitelist the sites you use internally — your own tools, your own docs, your own trackers — so Capsulla stays out of the way where it doesn't need to be. Install free — no account, no sign-in, no setup. Default rules are active immediately, and you can fine-tune them anytime from the extension's settings. Support: support@lockisecurity.com