Random UUID Generator
Generate UUID v4 values for test data and sample API payloads. Choose a quantity, copy one or all, or download CSV and JSON. Initial values are shared examples; generated values are test fixtures, not reserved IDs.
Updated
1f08341c-b836-4dd3-91a2-61d331079dfeb1f60c04-b0d8-4ad2-96c9-c27d28257c292b822d43-20b5-4b69-82bb-1d8e37946f6a
Choose 1, 5, 10, 25, 50 or 100 values and press Generate. Copy one UUID, copy the batch as newline-separated text, or download CSV and JSON. Downloads use a guid field and contain exactly the values currently displayed. These samples suit test rows, documentation and mock API requests.
A UUID is a 128-bit identifier, also called a GUID. Its usual text form contains 32 hexadecimal digits and four hyphens. In a version 4 UUID, the third group starts with 4 and the fourth starts with 8, 9, a or b. RFC 9562 is the current standard and replaces RFC 4122; v4 allocates 122 bits to random or pseudorandom data.
This tool uses the site's seeded Faker identity engine. The initial examples are shared by visitors, and the engine reduces each seed to a 32-bit number. Repeated seeds or seed-hash collisions can therefore repeat a UUID. Do not apply an ideal 122-bit collision estimate to this implementation or treat its output as a uniqueness guarantee. For a duplicate-key test, deliberately reuse one value rather than waiting for a random duplicate.
UUID v4 format (RFC 9562)
| Group | Length | Example |
|---|---|---|
| Group 1 | 8 hex | f47ac10b |
| Group 2 | 4 hex | 58cc |
| Group 3 | 4 hex; starts with 4 | 4372 |
| Group 4 | 4 hex; starts with 8, 9, a or b | a567 |
| Group 5 | 12 hex | 0e02b2c3d479 |
The canonical UUID string is 32 hexadecimal digits in five groups separated by hyphens.
Seeded test UUIDs versus application-generated IDs
The installed Faker.js 9.9.0 exposes faker.string.uuid() for v4 values. Calling faker.seed(42) again can replay a sequence when the Faker version and call order stay fixed. The full identity engine consumes other random values before its UUID call, so a standalone Faker call will not necessarily match this page's output. See deterministic test data for a version-pinned example.
For IDs assigned by a running Node.js application, crypto.randomUUID() uses a cryptographic pseudorandom generator. It does not share Faker's seeded replay behavior. Generate application IDs in your own system and enforce its uniqueness requirements there; a public sample page cannot reserve an identifier for you. This tool produces v4 fixtures. The UUID and GUID guide explains versions, including time-ordered v7.
Guides on technical identifiers
Frequently asked questions
What is a UUID?
A UUID (universally unique identifier), also called a GUID, is a 128-bit value written as 32 hexadecimal digits in an 8-4-4-4-12 pattern. It is used as a unique key without needing a central registry.
Are generated UUIDs unique?
Uniqueness is not guaranteed. This page uses seeded test data, its initial examples are shared, and repeated seeds can reproduce values. Check duplicates when your fixture requires distinct keys. Generate production identifiers within your application.
Can I generate many UUIDs at once?
Yes. Select up to 100 and press Generate. Copy all produces one UUID per line; CSV and JSON exports use a guid field and contain the displayed batch.
Is the UUID generator free?
Yes — free and unlimited, no sign-up.