What is a ULID?

A ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier encoded as a 26-character Crockford base32 string. It combines a 48-bit millisecond timestamp with 80 bits of randomness, so it is unique like a UUID but sorts by creation time.

How do I convert a ULID to a UUID?

ULIDs and UUIDs are both 128-bit values, so converting between them is a lossless re-encoding of the same bits. Paste a ULID into the free converter at ulidtools.com to get its UUID representation instantly - the conversion runs entirely in your browser.

Can I extract the timestamp from a ULID?

Yes. The first 10 characters of a ULID encode a 48-bit Unix timestamp in milliseconds. Every converter on ulidtools.com decodes and displays this timestamp, so you can see exactly when a ULID was created.

What is the difference between ULID and UUID v7?

Both embed a 48-bit millisecond timestamp and sort by creation time. UUID v7 (RFC 9562, 2024) uses the standard 36-character UUID format with 74 random bits; ULID uses a more compact 26-character base32 string with 80 random bits. If your ecosystem expects UUIDs, use UUID v7; if you want shorter, URL-friendly, case-insensitive IDs, use ULID.

Can I store a ULID in a UUID database column?

Yes. A ULID is 128 bits, the same size as a UUID, so it fits natively in a Postgres uuid column or any 16-byte binary field. Convert the ULID to UUID format first - it is more compact than storing the 26-character string and keeps index locality thanks to the timestamp prefix.

Is this ULID generator free?

Yes. All tools on this site are free and run entirely in your browser - no sign-up, no server round-trips, and your data never leaves your machine.