UUID Generator
Generate random v4 UUIDs in bulk, ready to copy.
Use on any page (bookmarklet)
Want UUID Generator without leaving the page you're on? Drag the button below to your bookmarks bar, then click it on any website to open UUID Generator right there — it runs entirely in your browser.
Use responsibly: a bookmarklet runs on whatever page you click it on. Avoid sensitive sites such as online banking, payment, or healthcare pages — you run it at your own risk. Everything is processed locally and no data is sent anywhere. See our Terms.
- Show your bookmarks bar if it's hidden — Ctrl+Shift+B (⌘+Shift+B on Mac).
- Drag the button above onto the bookmarks bar.
- Open any website and click the bookmark — the UUID Generator panel appears in the top-right corner. Use ✛ to move it between corners, or ›/‹ to tuck it against the edge and pull it back out.
- Click the bookmark again (or the ✕) to close it.
Note: a few sites with strict security policies may block bookmarklets.
Examples
Standard v4 UUIDs
Output
3f50a7b2-8c19-4e7a-9b3d-1c5e6f0a2d44 b1e2c3d4-5a6f-4b8c-9d0e-1f2a3b4c5d6e
Uppercase, no hyphens
Output
9C8B7A6D5E4F4A3B2C1D0E9F8A7B6C5D
About this tool
This free online UUID generator creates random version 4 (v4) UUIDs in bulk, ready to copy. Choose how many you need, toggle uppercase or hyphens, and click Generate. Everything runs in your browser using the Web Crypto API with no upload, so the IDs are cryptographically random and never leave your device.
How to use
- Enter how many UUIDs you want (up to 1,000).
- Optionally switch on Uppercase, or switch off Hyphens.
- Click Generate, then Copy all to grab the list.
What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value written as 32 hexadecimal digits in five hyphen-separated groups — for example, 123e4567-e89b-42d3-a456-426614174000. Version 4 UUIDs are generated from random data, so they can be created anywhere without coordinating with a central server and still be practically guaranteed not to collide.
When to use one
- Database keys — generate an ID on the client before saving, with no auto-increment round-trip.
- Request / trace IDs — tag a log entry or API call so you can follow it across systems.
- File and resource names — avoid clashes without a naming authority.
- Idempotency keys — safely retry an operation without repeating its effect.
A UUID is an identifier, not a secret — don't use one as a password or token. For those, generate a strong password or a random string instead.
Frequently asked questions
Is this UUID generator free?
Yes — it's a completely free online UUID generator with no sign-up. Generate as many UUIDs as you need.
Are the UUIDs generated on a server?
No. UUIDs are generated in your browser using the Web Crypto API with no upload, so nothing is sent to or stored on a server.
What kind of UUIDs are these?
Random version 4 (v4) UUIDs as defined by RFC 4122 — 122 bits of randomness, the most common type for database keys and identifiers.
What's the difference between a UUID and a GUID?
None in practice — GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit value. This tool's output works wherever a UUID or GUID is expected.
Are the UUIDs guaranteed to be unique?
v4 UUIDs are not strictly guaranteed unique, but the chance of a collision is astronomically small, so they're treated as unique in practice.
Can I generate UUIDs in bulk?
Yes — enter how many you want (up to 1,000) and click Generate, then Copy all to grab the whole list at once.
Can I get uppercase UUIDs or remove the hyphens?
Yes. Toggle Uppercase for capital letters, and switch off Hyphens for a compact 32-character form.
Learn more
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