UUID / GUID Generator
Generate UUID v4 identifiers — the same thing developers often call a GUID — individually or in bulk.
A GUID is a UUID
GUID (Globally Unique Identifier) is Microsoft's name for the same concept as a UUID (Universally Unique Identifier). A v4 UUID and a "GUID" are the same 128-bit value — this generator produces both under one name.
How to use the uuid / guid generator
- Choose a version: v4 (random, default), v7 (time-ordered), or the all-zero nil UUID.
- Set how many you need (up to 500).
- Toggle uppercase or remove hyphens if your use case needs it.
- Click "Copy all" to grab the full list.
How it works
UUID v4 values are generated with the browser's native crypto.randomUUID(), which uses a cryptographically secure random number generator — the same guarantee used by v4 UUID libraries in any language. UUID v7 values embed a millisecond-precision timestamp in the first 48 bits followed by random bits, so sorting v7 UUIDs also sorts them by creation time, which is useful as a database primary key. A GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit value as a UUID — there is no technical difference between a v4 UUID and a "GUID."
Examples
| Input | Result |
|---|---|
| Version: v4 | e.g. 3fa85f64-5717-4562-b3fc-2c963f66afa6 |
| Version: v4, no hyphens, uppercase | e.g. 3FA85F6457174562B3FC2C963F66AFA6 |
Frequently asked questions
Is a GUID the same as a UUID?
Yes. GUID is simply Microsoft's name for the same concept as a UUID. A v4 UUID and a "GUID" are the identical 128-bit value format.
Are these UUIDs cryptographically random and safe to use as secrets?
Yes — v4 UUIDs here are generated with crypto.randomUUID(), which draws from your browser's cryptographically secure random number generator, not Math.random().
How many UUIDs can I generate at once?
Up to 500 per click, with one click to copy the whole list.
What's the difference between v4 and v7?
v4 is fully random. v7 embeds a timestamp so values generated later always sort after earlier ones — useful for database keys where sort order matters.
What is the nil UUID used for?
The nil UUID (all zeros) is a reserved value meaning "no UUID" or "not set," used as a sentinel in some systems.