Identify

What it's for

Find out what an unfamiliar piece of text is: an encoding such as Base64 or hex, a token such as a JSON Web Token (JWT), a hash, a UUID, a timestamp, a data format such as JSON or YAML, or a classical cipher. Each guess comes with its reason, what it decodes to where that helps, and a link to the tool that handles it.

For example, when a log, an email header or a puzzle hands you a string like aGVsbG8gd29ybGQ= and you don’t know where to start, paste it here first.

How to use it

Paste the text. The guesses update as you type, the most likely first, each marked very likely, likely, possible or a long shot. Where a guess decodes to something readable, it’s shown under Reads as.

The link opens the matching tool. For tools that keep their input in links (such as JSON Format, Cron Explainer and Caesar), the text is filled in for you; for tools that handle secrets (such as the JWT Decoder) it isn’t, so the text never goes into an address, and you paste it there yourself.

Example

Paste this:

Phhw ph dw wkh rog eulgjh dw plgqljkw

The first guess is Caesar cipher, shift 3, reading as Meet me at the old bridge at midnight, with a link that opens Caesar / ROT13 set to decrypt with a shift of 3.

Good to know

The guesses come from patterns and statistics, so short text can fit several formats: 2315313154 could be a Unix time or a Polybius square, and 32 hex digits could be an MD5 or another 128-bit hash. A hash can’t be undone; the guess only names the algorithm. Cipher guesses need about 20 letters or more, and Vigenère and transposition can only be suggested, not solved, here: use the Cipher Cracker and Classical Ciphers for that.