UUID Generator
Create cryptographically random UUID version 4 identifiers using your browser's built-in random generator. Choose how many you need, toggle uppercase or hyphens to match your format, and copy them all at once. A v4 UUID carries 122 random bits, which makes accidental collisions effectively impossible even across billions of values generated independently on different machines — exactly why they are used for database keys, idempotency keys, test fixtures and distributed identifiers that must never clash. Generation happens entirely in your browser using the same secure randomness source as cryptographic tokens, so nothing is sent to a server.
How to use
- Set how many UUIDs to generate.
- Optionally toggle uppercase or remove hyphens.
- Press Generate for a fresh batch.
- Copy all of them with the Copy button.
Frequently asked questions
- What kind of UUIDs are these?
- Version 4 (random) UUIDs from crypto.randomUUID(), which uses a cryptographically secure random source.
- Are they guaranteed unique?
- v4 UUIDs aren't strictly guaranteed unique, but collisions are astronomically unlikely in practice.
- Can I remove the hyphens?
- Yes, toggle hyphens off to get a 32-character hex string.
- Is anything sent to a server?
- No. UUIDs are generated locally in your browser.
- When should I use a UUID instead of an auto-incrementing ID?
- UUIDs shine when IDs must be generated independently — by multiple servers, offline clients, or before a database round-trip — without any coordination. Auto-incrementing integers are smaller and naturally ordered, but need a central authority to hand them out; UUIDs trade size for that independence.
- Are these UUIDs sortable by creation time?
- No. Version 4 UUIDs are fully random and contain no timestamp, so they do not sort chronologically. If you need time-ordered identifiers, look at UUID v7 or ULID, which embed a timestamp in their leading bits.
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