Capsulla — Lightweight Data Leak Prevention
Capsulla checks what you paste, upload, or download for sensitive data — credit card numbers, SSNs, API keys, and more — before it leaves your browser. No account, no setup, no cloud dependency.
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.
Luhn-verified card detection
Card-number matches are checked against a Luhn checksum before Capsulla reacts, so a random 16-digit number doesn't trigger a false alarm.
File upload & download protection
Block uploads and downloads by file type — stop an executable from being downloaded, or a spreadsheet from being dragged into the wrong upload field.
Custom rules, your patterns
The built-in rules cover the common cases. Add your own regex patterns and choose whether Capsulla should warn, block, or mask.
100% local, no accounts
Every check runs on your device. Nothing you paste, upload, or download is ever sent anywhere — no sign-in required.
Warn, block, or mask
Choose how Capsulla reacts per rule — a soft warning, a hard block, or an automatic mask that replaces just the sensitive part.
How it works
Install the extension
Add Capsulla to your browser — default detection rules are active immediately, no setup required.
Work as usual
Paste, upload, and download normally. Capsulla checks everything in the background, in real time.
Get warned before it's too late
If something sensitive is about to leave your browser, Capsulla warns, blocks, or masks it — your call.
What is DLP?
Data Leak Prevention (DLP) means catching sensitive information before it accidentally leaves your control — a card number pasted into a support ticket, a spreadsheet full of SSNs dragged into the wrong upload field. Capsulla does this locally, inside your browser, without routing your data through a cloud service.
Detected by default
- 1Credit card numbers (Luhn-verified)
- 2IBAN numbers
- 3Social Security Numbers
- 4Email addresses
- 5Phone numbers
- 6AWS access keys
- 7Private keys (PEM format)
Nothing you paste, upload, or download ever leaves your device — except anonymous product analytics. Read our Privacy Policy.