About the UUID Generator
This UUID generator produces RFC 4122 version 4 (random) UUIDs using your browser's native crypto.randomUUID. Version 4 UUIDs are 128-bit identifiers built almost entirely from cryptographically secure random bits, so collisions are astronomically unlikely and you can mint them independently without coordinating with a central service.
Use it whenever you need unique identifiers for database primary keys, API request IDs, correlation IDs in logs, test fixtures or message keys. You can generate a single UUID or a batch of many at once and copy them with one click. It all runs locally in your browser, so the identifiers are created on your device and nothing is uploaded.
How to use it
- Choose how many UUIDs you want — one or a batch.
- Click generate to create version 4 UUIDs instantly.
- Copy a single UUID or the whole list with one click.
- Regenerate at any time for a fresh set.
Examples
- Generate one UUID for a new database row: 3f2504e0-4f89-41d3-9a0c-0305e82c3301.
- Generate 100 UUIDs at once to seed test fixtures or mock data.
- Create a correlation ID to trace a single request across microservice logs.
Frequently asked questions
What is a version 4 UUID?
A version 4 UUID is a 128-bit identifier defined by RFC 4122 whose bits are mostly random, apart from fixed version and variant markers. It is the most common UUID type for general-purpose unique IDs.
How unique are these UUIDs?
Each v4 UUID has 122 random bits, giving about 5.3 x 10^36 possibilities. The chance of a collision is negligible for any realistic number of identifiers.
Is generation done locally or on a server?
Entirely locally. The tool uses your browser's crypto.randomUUID, so UUIDs are generated on your device and nothing is sent anywhere.
Can I generate many UUIDs at once?
Yes. You can produce a batch of UUIDs in a single action and copy the entire list, which is handy for seeding databases or test data.
What is the difference between UUID v4 and UUID v7?
Version 4 is fully random and has no order. Version 7 embeds a timestamp so the IDs sort chronologically. For time-sortable IDs, use the ULID/UUIDv7 generator instead.
Are version 4 UUIDs good for database primary keys?
They guarantee uniqueness without coordination, but their randomness can hurt index locality. If insert ordering matters, consider UUID v7 or ULID, which are time-sortable.