UUID Generator
Generate RFC 4122 v4 UUIDs in bulk with crypto randomness.
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About this tool
UUID Generator produces version 4 (random) UUIDs using crypto.getRandomValues, formatted per RFC 4122 — the standard identifiers used for database keys, API resources, and distributed systems. Generate one or hundreds at once, toggle uppercase output, and copy the whole batch.
Because v4 UUIDs are 122 bits of randomness, collisions are astronomically unlikely even at massive scale. Generation is fully local.
How to use
- Choose how many UUIDs to generate.
- Toggle uppercase if your system expects it.
- Click generate.
- Copy individual UUIDs, copy all, or download as a text file.
Frequently asked questions
A 128-bit identifier with 122 random bits, rendered as 32 hex digits in five groups (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx). The "4" marks the version.
Theoretically yes, practically never — you would need to generate billions per second for a century to reach even a tiny collision chance.
Functionally nothing. GUID is Microsoft's name for the same 128-bit structure; a v4 UUID is a valid GUID.
Yes — they use the browser's crypto.getRandomValues, not Math.random().