What encoding is this?
Paste a string you don't recognise. Every decoder on the site tries it at once, and you can ask for a plain-English explanation of what it is and where it came from.
Results appear as you type.
Sends the string to an AI model for a short explanation. Don't paste live passwords or keys.
Reading the clues yourself
- Alphabet. Only 0/1 is binary; 0–9 a–f is hex; A–Z a–z 0–9 + / = is Base64.
- Length. Base64 comes in multiples of 4. Hex in pairs. Binary in groups of 8. Fixed lengths of 32, 40 or 64 hex characters are hashes.
- Markers.
%means URL encoding;&…;means HTML entities;\umeans string escapes;Ãandâ€mean mojibake. - Prefixes.
eyJis Base64 for{", so it starts almost every JWT.data:is a data URI.0xis hex.
Questions people ask
How can I tell what encoding a string uses?
Look at the alphabet and length. Only 0 and 1: binary. 0–9 and a–f in pairs: hex. Letters, digits, + and / with length a multiple of 4, maybe ending in =: Base64. %XX sequences: URL encoding. &name; patterns: HTML entities. Starts with eyJ and has two dots: a JWT. This page checks all of these at once.
Can it decode a hash like MD5 or SHA-256?
No tool can. Hashes are one-way: a 32-character hex string is usually MD5, 40 is SHA-1, 64 is SHA-256. You can only hash a candidate and compare.
What does the AI explanation add?
The instant checks tell you which decoders succeed. The explanation (sent only when you press the button) looks at the whole string, names likely sources such as a cookie, JWT or data URI, spots nested layers and flags strings that look like secrets.
Is my string stored?
The instant checks run only in your browser. If you ask for an explanation, the string (up to 2,000 characters) is sent to our server and an AI model through Vercel AI Gateway to generate the answer; we do not store it. Don’t paste live passwords or API keys.