A Universally Unique Identifier (UUID) is a 128-bit value, typically written as 32 hex digits in the form 8-4-4-4-12, designed so that generating one independently anywhere is astronomically unlikely to collide with another.

What's special about version 4?

Version 4 UUIDs are generated from random (or pseudo-random) bits rather than from a timestamp or hardware address, per RFC 4122. This tool uses the Web Crypto API's crypto.randomUUID(), which is cryptographically secure.

Are these UUIDs generated on a server?

No — every UUID here is generated locally in your browser using crypto.randomUUID(). Nothing is transmitted or logged.

Can I generate more than one at a time?

Yes — use the bulk generator below to create up to 1,000 UUIDs at once, one per line.

This tool runs entirely in your browser. Nothing you paste is uploaded.

How you can check →

UUID Generator

Generators

Generate RFC 4122 v4 UUIDs — one at a time, or up to 1,000 in bulk. Uses the Web Crypto API, entirely in your browser.

UUID v4

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Bulk generate

Count Max 1,000

Results

UUID structure

A UUID is written as 32 hexadecimal digits grouped as 8-4-4-4-12 (e.g. xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx). The version (here, always 4) is encoded in the first digit of the third group, and the variant is encoded in the first digit of the fourth group.

Common use cases

Primary keys for database rows, generated client-side or server-side
Idempotency keys for API requests
Correlation/trace IDs for distributed logging
Unique filenames or object storage keys

Frequently asked questions

What is a UUID?: A Universally Unique Identifier (UUID) is a 128-bit value, typically written as 32 hex digits in the form 8-4-4-4-12, designed so that generating one independently anywhere is astronomically unlikely to collide with another.
What's special about version 4?: Version 4 UUIDs are generated from random (or pseudo-random) bits rather than from a timestamp or hardware address, per RFC 4122. This tool uses the Web Crypto API's crypto.randomUUID(), which is cryptographically secure.
Are these UUIDs generated on a server?: No — every UUID here is generated locally in your browser using crypto.randomUUID(). Nothing is transmitted or logged.
Can I generate more than one at a time?: Yes — use the bulk generator below to create up to 1,000 UUIDs at once, one per line.

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