UUID Generator
Create random version 4 UUIDs (GUIDs) in bulk, with uppercase option and one-click copy.
Generate UUIDs instantly
The UUID Generator creates random version 4 UUIDs (also called GUIDs) on demand — one at a time or in bulk. Choose how many you need, toggle uppercase, and copy individual values or the whole list with one click. Each UUID is generated locally using your browser's secure random number generator, so nothing is sent to a server.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to label information uniquely without a central authority. It is written as 32 hexadecimal digits in five groups separated by hyphens, like 3f2504e0-4f89-41d3-9a0c-0305e82c3301. UUIDs are everywhere in software: database primary keys, API request IDs, file names, session tokens, and distributed systems where two machines must generate identifiers that never collide.
Version 4 UUIDs
This tool generates version 4 UUIDs, which are produced from random (or pseudo-random) numbers. The version is fixed at the 13th digit and the variant bits are set per the standard, leaving 122 random bits. That is roughly 5.3 × 10³⁶ possible values — so many that the chance of generating the same one twice is effectively zero for any practical application.
How to use the generator
- Set the count (1 to 100).
- Optionally enable uppercase if your system expects it.
- Click Generate for a fresh batch.
- Copy a single UUID or use Copy all for the whole list.
Common uses for UUIDs
| Use case | Why UUIDs help |
|---|---|
| Database keys | Generate IDs on the client without round-tripping to the server. |
| Distributed systems | Multiple services create unique IDs with no coordination. |
| Idempotency keys | Safely retry API calls without duplicate side effects. |
| File / asset names | Avoid naming collisions for uploads. |
Are these UUIDs secure?
They are generated using the Web Crypto API's secure randomness when available, which is suitable for non-guessable identifiers. Note that UUIDs are designed for uniqueness, not secrecy — if you need a secret token, use a dedicated cryptographic token generator. For unique keys and IDs, version 4 UUIDs are an excellent, widely supported choice.
Private and free
Every UUID is created in your browser and nothing is logged or stored. Generate as many batches as you like, completely free.
Frequently asked questions
What version of UUID does this generate?
Version 4 — randomly generated UUIDs, the most common type for keys and identifiers.
Are the UUIDs truly unique?
Version 4 UUIDs have 122 random bits, so the probability of a collision is negligible for any realistic use.
Can I generate many at once?
Yes. Set any count from 1 to 100 and copy them all with one click.
Are UUIDs generated securely?
Yes, using your browser's cryptographically secure random generator. They are created locally and never sent anywhere.
Is a GUID the same as a UUID?
Yes. GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit identifier standard.