When to use a UUID
A UUID gives something an identity without asking a central server for the next number. A browser, a phone working offline and two separate databases can all create IDs at the same time and never clash, which is why UUIDs are used for database rows in distributed systems, file names, API request IDs and records that are merged later. A version 4 UUID has 122 random bits, so the chance of two ever matching is too small to matter in practice.
This generator uses the browser's crypto.randomUUID(), a cryptographically secure source, and produces up to 100 at a time in the standard 8-4-4-4-12 format. As database primary keys, random UUIDs make indexes grow out of order, which can slow inserts on very large tables; time-ordered formats such as UUIDv7 exist for that. They're also identifiers, not passwords: don't use one as a secret.
How to Use UUID Generator
- 1Set how many UUIDs you want to generate (1–100).
- 2Click 'Generate' to create them.
- 3Copy all UUIDs at once or regenerate a fresh batch.
Frequently Asked Questions
What is a UUID v4?
A Universally Unique Identifier generated from random numbers. The probability of collision is astronomically small: making them safe to use as unique IDs without a central registry.
Are these truly random?
Yes. They use the browser's crypto.randomUUID() which draws from a cryptographically secure random number generator.
Can I use these as database primary keys?
Yes. UUID v4 is widely used as a primary key in distributed systems where auto-increment integers aren't practical.
How many UUIDs can I generate at once?
Anything from 1 to 100 per batch. Copy them all in one go, one per line, or generate a fresh batch.
What do the parts of a UUID mean?
A v4 UUID is 32 hexadecimal digits in groups of 8-4-4-4-12. The first digit of the third group is always 4, the version, and the first digit of the fourth group is 8, 9, a or b, the variant. Everything else is random.
Is a UUID the same as a GUID?
Yes. GUID, globally unique identifier, is Microsoft's name for the same 128-bit format, and a v4 GUID is a v4 UUID.
About UUID Generator
UUIDs (Universally Unique Identifiers) are 128-bit values used as unique identifiers in databases, APIs, file systems, and distributed systems. Version 4 UUIDs are generated from random bits and are statistically guaranteed to be unique.
Our UUID Generator uses the browser's built-in crypto.randomUUID() function (a cryptographically secure source) to produce properly formatted v4 UUIDs in the standard 8-4-4-4-12 hyphenated format.