Getting started

cadenas (French for padlock) encrypts and decrypts a file with a password, right in your browser: no file and no password is ever sent over the Internet. The same tool is available on the command line.

The fastest way: open getcadenas.com, drop a file, choose a password, download the result.

Why cadenas?

You want to send a sensitive document by email, store a backup in the cloud or keep a file on a USB stick, and you just need a password on it. Existing tools are either command-line only, need to be installed, or are built for something else (archives, encrypted disks). cadenas does one thing: one file, one password, from any device with a browser.

Pick how to use cadenas

You want to…	Use
Encrypt or open a file without installing anything, even on a phone	the website
Send an encrypted file to someone	the website, with the "decrypt" page for the recipient
Automate, encrypt backups, work in a terminal	the command line
Offer cadenas on your own server or network	the Docker image
Add encryption to your application	the JavaScript library

All of them produce the same files: a file encrypted on the website opens on the command line, and the other way round.

Compared with other tools

	cadenas	age	7-Zip	VeraCrypt
Works in the browser, nothing to install	✅	❌	❌	❌
Works on a phone (iOS, Android)	✅	❌	❌	❌
Graphical interface	✅	❌	✅	✅
Command line	✅	✅	✅	✅
Encrypts a plain file (no volume to mount)	✅	✅	✅	❌
Authenticated encryption: any tampering is detected	✅	✅	❌ 1	❌ 2
Memory-hard password derivation (slows down GPU attacks)	✅ Argon2id	✅ scrypt	❌ 3	—
Reads and writes age files	✅	✅	❌	❌
Self-hostable web version (Docker)	✅	❌	❌	❌
Free and open source	✅	✅	✅	✅
Independent security audit	❌ not yet	—	—	✅ 4

¹ 7z archives check a CRC of the decrypted data, not a cryptographic tag.
² VeraCrypt volumes use XTS mode, which does not detect changes.
³ 7-Zip derives the key with iterated SHA-256.
⁴ Audited by Quarkslab in 2016.
—: depends on the version, or not checked by us.

Use something else when…

you want public-key encryption (age), a whole encrypted disk or hidden volumes (VeraCrypt), or compressed archives first and foremost (7-Zip).

Before you start

A forgotten password cannot be recovered

There is no backdoor and no recovery, for anyone. Keep your password somewhere safe: see Choose a password.

• The file name and its approximate size remain visible. To hide the name, use --hide-name on the command line.
• The .cadenas format has not been audited by independent specialists yet. If you need a widely reviewed format, choose the age format.