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How to Use
- 1Set the count to generate one or multiple UUIDs (up to 50 at once).
- 2Click Generate to create new v4 UUIDs using crypto-secure randomness.
- 3Click any UUID in the list to copy it individually.
- 4Use Copy All to copy the entire batch to your clipboard.
- 5Generate again for a fresh set of unique identifiers.
About UUID Generator
The UUID Generator creates version 4 universally unique identifiers using the Web Crypto API (crypto.randomUUID or crypto.getRandomValues) for cryptographically secure randomness. Generate a single UUID or bulk-create up to 50 at once.
UUIDs (also called GUIDs) are 128-bit identifiers formatted as 32 hex digits in 5 groups: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. The '4' indicates version 4, and 'y' is one of 8, 9, a, or b — conforming to RFC 4122.
Developers use UUIDs as primary keys in databases, API resource identifiers, session tokens, file names, message IDs, and any scenario requiring globally unique values without a central authority. The probability of collision is approximately 1 in 2^122.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier designed to be unique across space and time. Also known as GUID (Globally Unique Identifier) in Microsoft ecosystems.
Are these UUIDs cryptographically secure?
Yes. They are generated using the Web Crypto API, which provides cryptographically secure random values — far stronger than Math.random().
What is the difference between UUID v4 and other versions?
UUID v4 is based entirely on random numbers. V1 uses timestamps and MAC addresses, v3/v5 use name-based hashing. V4 is the most commonly used version for general-purpose unique IDs.
Can two UUIDs ever be the same?
Theoretically possible, but the probability is astronomically low — about 1 in 2^122 (5.3 × 10^36). You would need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of one collision.
Can I use UUIDs as database primary keys?
Yes. UUIDs are widely used as primary keys in distributed databases (PostgreSQL, MongoDB, etc.) because they can be generated independently without coordination between nodes.