UUID and ULID Generator
Generate random UUID v4, time-ordered UUID v7 or ULIDs, using the browser's cryptographic random source.
About
Generate identifiers that are unique without coordination between systems. Version 4 is purely random, version 7 puts a timestamp first so values sort roughly by creation time, and ULIDs do the same in a shorter, case-insensitive form. All three come from the browser cryptographic random source.
How to use
- Choose the type of identifier you need.
- Set how many you want, up to one hundred.
- Generate and copy the list.
Frequently asked questions
Which should I use as a database key?
Version 7 or a ULID, because they are time-ordered and keep index inserts near the end of the tree. Random version 4 keys scatter writes and fragment the index over time.
Are these safe to use as secrets?
No. They are unique, not unpredictable in the way a token needs to be. Use a dedicated random token generator for anything that grants access.
Why does version 7 sort correctly?
The first 48 bits hold a millisecond timestamp, so lexicographic order matches creation order until the timestamp overflows, which is far in the future.