About this tool
Encrypt and decrypt text with several classical and modern algorithms. The classical ones (Caesar, ROT13, Vigenère, Atbash) are useful for puzzles, games, and historical introductions to cryptography. The modern one (AES-256-GCM) provides real confidentiality for sensitive texts. Encryption happens locally in the browser, without the text leaving your device.
How to use
- Paste the text to encrypt (or decrypt).
- Pick the algorithm. For real security, use AES-256-GCM. For educational puzzles, use Caesar, Vigenère, ROT13, or Atbash.
- Enter the password or key (depending on the algorithm).
- Click the button. To decrypt, use the same algorithm and key that were used to encrypt.
Frequently asked questions
- When should I use AES versus a classical cipher?
- AES-256-GCM for any real confidentiality case (private messages, sensitive files, personal data). Classical ciphers (Caesar, Vigenère, ROT13, Atbash) are easy to break and only useful for educational purposes, puzzles, escape rooms, or games where security isn't the goal.
- Can I recover encrypted text without the key?
- For AES-256-GCM, no. The encryption is cryptographically secure and without the correct key the text is impossible to recover with current technology. For classical ciphers, yes, there are manual or automatic methods to break them with some effort, especially if the text is long or you know the language.
- What happens if I lose the password?
- For AES, you lose access to the text. There's no "password recovery", that would defeat the purpose of encryption. So when encrypting important content, make sure the key is stored somewhere safe and separate from the encrypted text.