UUID生成

What is UUID Generator?

UUID Generator creates random UUID v4 identifiers. A UUID (Universally Unique Identifier) is a 128-bit number formatted as 32 hex digits in groups of 8-4-4-4-12 (e.g. 550e8400-e29b-41d4-a716-446655440000). UUID v4 uses random or pseudo-random bits, making collisions extremely unlikely.

How to use

1. Click Generate to create a new random UUID v4.
2. Click Copy to copy it to your clipboard.
3. Generate as many UUIDs as needed; each one is independently random.

Common use cases

• Primary keys in relational and NoSQL databases
• Idempotency keys for API requests
• Filenames or object keys in storage systems
• Session or transaction identifiers

FAQ

What is the probability of a UUID collision?

UUID v4 has 122 random bits (~5.3 × 10^36 possible values). The probability of generating a duplicate is negligible for practical applications; you would need to generate over a billion UUIDs per second for centuries before expecting a collision.

What is the difference between UUID v4 and v7?

UUID v4 is fully random. UUID v7 (a newer standard) embeds a millisecond-precision timestamp, making UUIDs sortable by creation time and useful for database indexing.

Is UUID the same as GUID?

Functionally yes. GUID (Globally Unique Identifier) is Microsoft's implementation of the UUID standard. They use the same format and are interchangeable in most contexts.