ULID Generator
NewGenerate Universally Unique Lexicographically Sortable Identifiers (ULIDs).
Decoded timestamp
Generate a ULID to inspect its 48-bit timestamp.
Total generated
0
Length
26 chars
ULID = 48-bit timestamp (ms since epoch) + 80-bit random data encoded with Crockford Base32.
Timestamp breakdown
Frequently Asked Questions
How many ULIDs can I generate at once?
From 1 to 100. The batch size input is clamped into that range, and the page defaults to generating 10 at a time.
Are the generated ULIDs lexicographically sortable?
Yes. The first 10 characters encode the current timestamp in Crockford Base32, so the strings sort by time across different milliseconds.
Does this use monotonic ULIDs for items created in the same millisecond?
No. It generates a fresh random 80-bit tail every time instead of incrementing within the same millisecond, so same-ms ULIDs are not guaranteed to stay in generation order.
Why does every ULID stay 26 characters long?
Because this tool always builds them as 10 Base32 characters of timestamp plus 16 Base32 characters of random data, which is the standard ULID length.
What is the decoded timestamp panel showing me?
It reads the first 10 characters back into the original 48-bit millisecond timestamp. The summary shows the first ULID's timestamp as both a local date/time and raw epoch milliseconds.