ULID Validator
Paste a ULID to check whether it is valid — complete with the reason if it is invalid and a component breakdown if it is valid. Everything is processed on your device.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
01ARZ3NDEKTSV4RRFFQ69G5FAV
Example Output
✓ VALID — timestamp decoded
How to Use
- 1Paste the a ULID you want to check into the input box.
- 2If the tool offers extra options (e.g. dialect, flags, or variant), set them as needed.
- 3Click Validate (or press Ctrl+Enter).
- 4Read the result badge — VALID, INVALID, or VALID with a warning — along with the details and the list of issues, if any.
About ULID Validator
ULID Validator checks whether a string is a valid ULID: 26 Crockford Base32 characters (no I, L, O, U), with the first character 0–7 so the 48-bit timestamp does not overflow. It also decodes the timestamp into a readable date.
A ULID is a time-sortable alternative to a UUID. Validation confirms the format is correct before using it as a sortable identifier.
FAQ
Is my data sent to a server?
No. All validation runs in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.
How is this validator different from a parser or formatter?
A validator answers one question: is this input correct/valid? It returns a valid/invalid badge with the reason. A parser breaks input into its components, and a formatter tidies its layout. Use a validator when you just need to confirm something is sound before using it.