ULIDs contain a 48-bit timestamp and an 80-bit random component, encoded as 26 Crockford base32 characters. This tool accepts upper- or lowercase input and checks the 128-bit limit.
What the result means
The first ten characters encode the Unix millisecond timestamp. The remaining sixteen characters encode the random component. The timestamp is data in the identifier, not evidence of when a trusted system created it.
The largest representable ULID begins with 7. Values beginning with 8 or higher overflow 128 bits. Letters I, L, O, and U are not part of the canonical alphabet.
Frequently asked questions
- Can I decode a UUID here?
- Use the UUID decoder for UUID v1, v6, and v7. ULID uses a different text encoding.