Choose an algorithm and key
Pick AES or another supported algorithm, then enter a secret key or generate a random one.
Encrypt and Decrypt Text Online Free
Protect a short message with a secret key using AES, DES, 3DES, RC4, Rabbit or TripleDES. Generate a random key, encrypt, then decrypt again with the same algorithm and key. Everything happens in your browser.
Algorithm:
Three simple steps
How to Encrypt Text Online
Symmetric encryption needs one key for both directions, so keep it somewhere safe.
Encrypt the text
Type or paste the message and select Encrypt. The ciphertext appears in the result area, ready to copy.
Decrypt it again
Paste the ciphertext back with the same algorithm and the same key, then select Decrypt to recover the original text.
Algorithm guide
Which Symmetric Algorithm Should You Pick?
AES is the sensible default. The others are here for compatibility and for learning.
| Algorithm | Status | Typical use |
|---|---|---|
| AES | Recommended | Anything new, from short messages to application data |
| 3DES / TripleDES | Legacy | Older payment and enterprise systems that still require it |
| DES | Obsolete | Learning material and compatibility with very old systems |
| RC4 | Obsolete | Historical protocols, not suitable for new work |
| Rabbit | Niche | High speed software encryption experiments |
Keep your key safe: this tool cannot recover a lost key. Store it in a password manager, and remember that a short or guessable key weakens even a strong algorithm.
Free encryption tool
Quick Symmetric Encryption Without the Setup
Everything you need for a one-off encrypt, decrypt or compatibility check.
Random key generation
Create a strong random key with one click, then copy it to your password manager.
Key stays hidden
The key field is masked by default and can be revealed or copied whenever you need it.
Nothing leaves the browser
Encryption runs with JavaScript on your device, so no plaintext or key is uploaded.
Two way by design
Encrypt and decrypt use the same controls, which makes it easy to verify a round trip.
Questions and answers
Text Encryption FAQ
Is my text uploaded to a server?
No. Encryption and decryption run with JavaScript in your browser, so your plaintext, your key and the result never reach the 73hi server.
Which algorithm should I use?
Use AES for anything that matters. DES, 3DES, RC4 and Rabbit are included for compatibility with older systems and learning material, but they are not recommended for new work.
What happens if I lose the key?
The text cannot be recovered. Symmetric encryption needs the same key to decrypt, and because the key never leaves your device, 73hi has no way to restore it.
Can I decrypt text encrypted by another tool?
Often yes, if that tool uses the same algorithm, the same key handling and the same output format as CryptoJS. Tools that add their own salt, IV or encoded envelope usually require matching settings.
Is this a replacement for proper data protection?
No. This is a convenience tool for short messages and quick checks. Protect sensitive data with a reviewed, well maintained library and a scheme that provides authenticated encryption.
Does the tool work on mobile?
Yes. The page is responsive and the encryption runs the same way in any modern mobile browser.