UUID Generator
Generate RFC 4122 v4 UUIDs — cryptographically random, browser-only, never stored. Generate up to 50 at once.
How many?
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information without a central authority. The v4 variant uses cryptographic randomness for 122 of its 128 bits, making collisions so unlikely (1 in 5.3 × 10³⁶) they are considered impossible in practice.
UUIDs are used as database primary keys, session tokens, file identifiers, API resource IDs, and idempotency keys — anywhere collision-resistant unique identification is needed across distributed systems.
UUID Format
A standard UUID v4 looks like: 550e8400-e29b-41d4-a716-446655440000
- 32 hexadecimal characters (128 bits total)
- Grouped as 8-4-4-4-12, separated by hyphens
- Third group always starts with "4" (version indicator)
- Fourth group starts with "8", "9", "a", or "b" (variant indicator)
- Remaining 122 bits are cryptographically random
Privacy
All UUIDs are generated locally in your browser using crypto.getRandomValues(). Nothing is sent to any server — not your count, not the generated values, nothing.