How to use the UUID Generator
- Choose how many UUIDs you need.
- Pick the format (hyphens, case, braces, quotes).
- Copy them or download a .txt file.
About this tool
A version-4 UUID is 128 bits of which 122 are random, written as 32 hex digits like 3f2b8c1e-9d4a-4f6b-8e2a-1c7d5e9f0a3b. The chance of two ever colliding is so small that systems can create IDs independently — on phones, servers and browsers — without checking a central counter. Microsoft calls the same thing a GUID.
These UUIDs come from crypto.randomUUID(), the browser’s cryptographically secure generator. They are unpredictable, but don’t use them as passwords or secret tokens where a purpose-built secret is expected.
Frequently asked questions
What’s the difference between a UUID and a GUID?
They’re the same standard. GUID is Microsoft’s name; the format is identical.
Can two UUID v4 values be the same?
In theory yes, in practice no: you would need to generate billions per second for many years to expect a single duplicate.
Which version should I use?
Version 4 (random) suits most needs. If you need IDs that sort by creation time in a database, look at UUID version 7.