Cipher & encoding identifier
Paste text and it auto-detects and decodes Base64, hex, Morse, Caesar, XOR and more — ranked by how readable each result is. Runs entirely in your browser.
What it detects
Base64, Base32, hexadecimal, binary, decimal ASCII, URL-encoding, HTML entities, Morse code, Caesar (all shifts, auto-scored), ROT13, ROT47, Atbash, reversed text and single-byte XOR. Each candidate is scored by how English-like its output is, so the real answer usually floats to the top.
Frequently asked
How does the ranking work?
Every decoder runs on your text; each result is scored on printable-character ratio, English letter-bigram frequency and common words. The most readable output ranks first — but check the others, since short strings can be ambiguous.
Is my text uploaded?
No. Every decoder is plain JavaScript running in your browser. Your text never leaves your device — which is exactly what you want for a CTF flag or anything sensitive.
It didn't crack my cipher — why?
Keyed ciphers (Vigenère without a guessable key, AES, RSA) and custom schemes can't be brute-forced from the string alone. This tool covers the encodings and classical ciphers that appear most in CTFs; for the rest it narrows down what you're looking at.