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UUID Generator

UUIDs (Universally Unique Identifiers) are 128-bit identifiers used as database keys, request IDs, session tokens, and anywhere you need a globally unique value without coordination. We generate v4 (random) UUIDs using your browser's crypto.randomUUID() — cryptographically secure.

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Examples

A single UUID v4
Output3f8c0e2a-9b1d-4e7f-bc52-1a8d4e9f5a3b

The "4" in the third group identifies the version.

Bulk generation
Output… 100 UUIDs, one per line …

Pick a count up to 1,000 — useful for seeding databases.

Frequently asked questions

What is the difference between UUID v1 and v4?

v1 is timestamp + MAC-address based (reveals when and where it was generated). v4 is fully random. v4 is the default for most applications because it leaks no information.

Are UUIDs really unique?

v4 UUIDs draw 122 random bits. The chance of collision is astronomically small — you can generate trillions before any real risk of a duplicate.

Should I use UUIDs as primary keys?

It is fine, but be aware: UUIDs are 16 bytes vs 4-8 for integer IDs, and random UUIDs hurt index locality. If those matter, consider UUID v7 (time-ordered) or auto-increment integers.

GUID vs UUID — same thing?

Yes. GUID is Microsoft's name for the same format. Treat them as identical.

Is this generator cryptographically secure?

Yes. We use crypto.randomUUID() in your browser, which draws from a cryptographically secure random source.

About this tool

UUID Generator runs entirely in your browser using standard Web APIs. No data is sent to any server. The source for this tool is in our public GitHub repository.

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Why this tool

vs typical free web-tool sites

1vwTypical free site
PriceFreeFree
Signup requiredNoOften (for premium features)
Ads inside the toolNoYes (banner + video)
Data sent to serverNo (browser-only)Yes (inputs analyzed for ads)
Total tools96Often <20 or scattered across sites
Bookmarkable URL per toolYesMixed
Loads in under 1sYes (static)Often slow (ad tracking)
MultilingualEN / ES / PT / FR / DEUsually EN only
Open sourceYesNo