Encode & Crypto
Base64 Encode / Decode
Encode text to Base64, or decode it back.
Encode & Crypto
Caesar Cipher
Shift letters by any amount with the Caesar cipher.
Tool Panel
Processed locallyAbout Caesar Cipher
The Caesar cipher shifts each letter by a fixed number of positions. Shift range: -25 to 25 Only letters are processed; everything else stays as it is ROT13 is the Caesar cipher with a shift of 13
- 1
The shift is taken modulo 26, so 29 behaves as 3 and -1 as 25 — negative and oversized shifts both work.
- 2
Only Latin letters are touched, each case wrapping inside its own range; digits, punctuation, CJK and emoji pass through untouched.
- 3
Encryption and decryption are one function: decoding just negates the shift, so both directions can be checked against the same text.
- 1
Type the text
The sample is HELLO WORLD; output updates live as you type or change the shift, no Convert click needed.
- 2
Change the shift
Use the number field (-25 to 25) to try offsets until a version reads as plain text.
- 3
Switch to Decode to restore
Keep the same shift and flip direction. If the shift is unknown, trying 1 through 25 enumerates every possibility.
No. There are 26 possible keys — a shift of 0 is the plain text — and trying them all breaks it instantly. It suits puzzles, teaching and demos, not protecting real data.
ROT13 is the shift-13 special case, and it is self-inverse: applying it twice returns the original because 13 × 2 = 26. Set the shift here to 13 and you have ROT13.
Related tools
View allEncode & Crypto
Base64URL Encode
Produce URL-safe Base64 without padding characters.
Encode & Crypto
Encode & Crypto
Base32 Encode / Decode
Encode or decode text using the Base32 alphabet.
Encode & Crypto
Encode & Crypto
Base36 Encode / Decode
Encode or decode numbers and text in Base36.
Encode & Crypto
Encode & Crypto
Base58 Encode / Decode
Encode or decode with Base58, the alphabet Bitcoin addresses use.
Encode & Crypto
Encode & Crypto
Binary Encode
Turn text into its 0 and 1 representation.
Encode & Crypto
Encode & Crypto
Binary Decode
Turn a binary string back into readable text.
Encode & Crypto
Encode & Crypto
Hex Encode
Convert text to a hexadecimal string.
Encode & Crypto