Caesar Cipher

Encrypt, decrypt, and brute-force Caesar cipher text with real-time output and adjustable shift values

Platte Tekst

0 characters

Ciphertext

Voer in tekst op de left naar see resultaten

Caesar Cipher

Encrypt, decrypt, and brute-force Caesar cipher text with real-time output and adjustable shift values

Functies

  • Encrypt / decrypt with a configurable shift (0–25)
  • Shift 13 = ROT13 (the classic "rotate by half the alphabet" variant)
  • Preserves case and passes through non-letters (digits, punctuation, whitespace) unchanged
  • Decrypt mode uses (26 − shift) so the inverse is just a one-click toggle
  • Runs entirely in your browser

Hoe te gebruiken

  1. Choose Encrypt of Decrypt modus met behulp van de toggle buttons.
  2. Instellen de shift waarde met behulp van de slider of nummer invoer (0-25).
  3. Type of plak uw tekst in de invoer area — de uitvoer updates in real time.
  4. Gebruiken de Brute Force knop naar see alle 26 possible decryptions.
  5. Klik Copy naar copy de uitvoer of elke brute-force resultaat naar uw klembord.

Tips en best practices

  • Caesar cipher is a teaching tool, not real cryptography — there are only 25 distinct shifts so brute-force is instant.
  • ROT13 (shift 13) is self-inverse: applying it twice returns the original text. Useful for obscuring spoilers.
  • Letter case is preserved: A→D, a→d at shift 3.
  • Non-letter characters (numbers, punctuation, spaces) pass through without change.
  • Runs entirely in your browser.

Veelgestelde vragen

What is a Caesar cipher?

A Caesar cipher is one of the oldest known encryption methods. It works by shifting each letter in the alphabet by a fixed number of positions. For example, with a shift of 3, A becomes D, B becomes E, and so on. It is named after Julius Caesar, who reportedly used it for military correspondence.

How does the shift value work?

The shift value determines how many positions each letter moves in the alphabet. A shift of 1 turns A into B, a shift of 13 turns A into N (this is ROT13), and a shift of 25 turns A into Z. A shift of 0 or 26 returns the original text.

What is the brute-force feature?

Since there are only 26 possible shifts (0-25), the brute-force feature shows the result of applying every possible shift to your input text. This is useful for cracking a Caesar cipher when you do not know the original shift value.

Is my data private?

Yes. All encryption and decryption happens entirely in your browser using JavaScript. No data is sent to any server or third party.

Can I use this for real security?

No. The Caesar cipher is a simple substitution cipher that can be broken trivially by brute force (only 26 keys). It is useful for learning about cryptography, puzzles, and CTF challenges, but not for protecting sensitive data.