Encodeur et décodeur de chiffre de César

Comment utiliser cet outil

1. 1

   Type or paste your message into the text area.

2. 2

   Drag the Shift slider to pick a key from -25 to +25; the default is 3.

3. 3

   Read the transformed text in the gray output box, which updates instantly as you type or move the slider.

4. 4

   To decode a message, set the shift to the negative of the value used to encode it (for example, use -3 to undo a +3 shift).

Qu'est-ce que le chiffre de César ?

Cas d'usage courants

• Teaching cryptography basics in a classroom by letting students watch each letter shift in real time.

• Solving or creating Caesar-cipher puzzles in escape rooms, ARGs, and CTF challenges.

• Decoding ROT13 text from forums or email by setting the shift to 13 or -13.

• Brute-forcing an unknown shift: scrub the slider through all 25 values until readable text appears.

• Generating lightly obfuscated spoiler text or hint answers that readers must shift back to reveal.

• Prototyping and debugging encode/decode logic before wiring up a stronger cipher in your own code.

Questions fréquentes