UUID Generator
Generate one or multiple UUID v4 strings using the browser's built-in crypto API. Options for uppercase, no-dashes format, and bulk generation up to 1000 UUIDs.
UUID v4 uses 122 bits of cryptographic randomness — the probability of a collision when generating 1 billion IDs is less than 0.00000001%. Generated using crypto.randomUUID() directly in your browser.
Click "Generate" to create UUIDs
Uses crypto.randomUUID() — cryptographically secure
Frequently Asked Questions
Are these UUIDs truly random?
Yes. UUIDs are generated using crypto.randomUUID() which uses a cryptographically secure random number generator.
What is the difference between UUID v4 and UUID v1?
UUID v4 is randomly generated using 122 bits of randomness. UUID v1 is time-based and includes the MAC address of the generating machine — which can expose identifying information. Use v4 for most cases.
Can two generated UUIDs ever be the same?
The probability is astronomically small — about 1 in 5.3×10^36 for any two UUIDs. Generating 1 billion UUIDs per second for 100 years gives a 50% chance of just one collision.
What format do you need — with or without hyphens?
Standard UUID format uses hyphens (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx). Some databases and APIs accept the compact no-hyphens form. Use the format selector to choose what you need.