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UUID & ULID Generator
Random UUIDs (v4, v7) and ULIDs.
Free. Runs in your browser: nothing you enter or open is uploaded.
Read the time inside a UUID v7 or ULID
The creation time is shown here.
Every ID is made in your browser with the Web Crypto random number generator. UUID v4 uses crypto.randomUUID where available. UUID v7 and ULID put the current time in milliseconds first, so they sort by creation time; IDs made in the same millisecond still sort in the order they were made.
How to use it
- Pick the type: UUID v4, UUID v7, ULID or NanoID.
- Set how many you need, up to 1,000, and the format options.
- Copy them all or download them as a text file.
Questions
Which one should I use?
UUID v4 is the safe default when you only need a unique ID. Use UUID v7 or ULID for database keys, because they sort by time and keep indexes compact. NanoID is shorter and URL friendly, good for public IDs in links.
Can two UUIDs ever be the same?
In practice, no. A v4 UUID has 122 random bits; you would need to make billions every second for many years before a repeat became likely.
Does a UUID v7 reveal anything?
It reveals when it was created, to the millisecond, as the reader below shows. If creation times are sensitive, use v4 instead.
What is the difference between a UUID v7 and a ULID?
Both start with a 48 bit timestamp followed by random bits. A UUID v7 is written as 36 hex characters with hyphens and fits UUID columns; a ULID is 26 characters of Crockford Base32, shorter and case insensitive.