About UUID Generator
The UUID Generator creates random UUID v4 (Universally Unique Identifier) strings instantly. Generate one or hundreds of UUIDs at once. Perfect for database primary keys, API tokens, session identifiers, test data, and any use case requiring globally unique identifiers.
UUID v4 generates its 128 bits almost entirely from random data, giving an astronomically low collision probability: you would need to generate over a trillion UUIDs per second for billions of years to have a 50% chance of a single collision.
Generated UUIDs follow the canonical format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 indicates version 4 and y is one of 8, 9, a, or b.
All UUIDs are generated using the browser's cryptographically secure random number generator (crypto.randomUUID or crypto.getRandomValues). Your data never leaves your device.
How to Use UUID Generator
Click Generate to create a UUID.
Increase the count to generate multiple UUIDs at once (up to 100).
Choose uppercase or lowercase output format.
Copy the result.
Examples
Frequently Asked Questions
What is UUID v4?
UUID v4 is a randomly generated 128-bit identifier standardized in RFC 4122. It is represented as 32 hexadecimal characters in the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx.
What is the difference between UUID and GUID?
They are the same thing. UUID (Universally Unique Identifier) is the standard term; GUID (Globally Unique Identifier) is Microsoft's term for the same concept.
Are the UUIDs cryptographically random?
Yes — crypto.randomUUID() or crypto.getRandomValues() is used, providing cryptographically strong randomness.
Can two generated UUIDs ever be the same?
Theoretically yes, but the probability is negligible. With UUID v4, the chance of collision is 1 in 2^122 per pair. You would need to generate quintillions of UUIDs to approach a 1% collision probability.
What is the difference between UUID v1, v4, and v7?
v1 is based on the machine's MAC address and timestamp (not recommended for privacy reasons). v4 is randomly generated. v7 is the newest standard — it encodes a millisecond timestamp for sortability while keeping most bits random.
Can I use UUIDs as database primary keys?
Yes — UUIDs are widely used as primary keys, especially in distributed systems where auto-increment integers would require centralized coordination. UUID v7 is better for database primary keys as its time-based prefix maintains insert order.