Offline encryption, Pri-Bit

A single-page HTML that encrypts and decrypts entirely on your device. No accounts, no server logs, works anywhere the file travels.

AES-256-GCM + PBKDF2 Zero server logs

Try it now Terms of service

Overview Pri-Bit at a glance

All operations run inside your browser; no data or keys leave your device.

Stores monthly sends in local storage; above thresholds you can optionally pay POL via Polygon to extend usage.

Encrypt/decrypt images up to 10 MB with previews and downloadable output.

Large payloads use chunked Base64 to avoid stack overflow; all offline.

How it works How it works

1) Agree on a shared secret Use another channel to agree on the secret.

2) Write the message Enter text and/or attach an image, then set expiry.

3) AES-256-GCM encryption PBKDF2-derived keys encrypt locally; attachments stay inside the envelope.

4) Paste & send Paste the block into email/SNS; recipients decrypt with the same HTML.

Note: after expiry, the decrypt view refuses to show content; only local counters change.

Security Security principles

Usage, language, and wallet counts live only in local storage.

Messages past expiry fail decryption and are immediately discarded.

Shared secrets are never stored. PBKDF2 derives a fresh key each time.

Image data is capped at 10 MB, chunk-encoded, and decrypted locally with auto-expiry cleanup.

Use cases Scenarios

Keep messages protected offline with only the HTML file, even where internet is blocked.

Share and retire sensitive data after projects without leaving traces.

Send photos or scans securely with the encrypted block and download-ready output.

What's new Latest implemented updates

FAQ Frequently asked questions

No. Only usage, language, and wallet counts are stored locally; nothing is sent server-side.

A wrong secret or expired block shows a failure state; content is never displayed.

Core features stay free. Only past a usage threshold do we request 1 POL on Polygon, and you can decline.

Get started Start now

Head to the live app to run encryption and decryption instantly in your browser.