UUID Generator

Generate random UUIDs (v4), timestamp-based UUIDs (v1), or bulk generate up to 100. All generated in your browser.

How it works: Click Generate to create a new UUID. Choose v4 (random) or v1 (timestamp-based). Use Bulk to generate multiple UUIDs at once. Paste a UUID in the validator to check its format and version.

Cryptographically random — recommended for most uses

1 generated
5fb56799-7129-4a9d-8278-8878cc665681

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. Also known as GUID (Globally Unique Identifier), UUIDs are formatted as 32 hexadecimal digits in five groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. The probability of generating duplicate UUIDs is so low that they can be considered practically unique.

UUID Versions Explained

UUID v1 is generated from the current timestamp and a node identifier (typically a MAC address). UUID v4 is generated using random or pseudo-random numbers and is the most commonly used version. UUID v4 has 122 random bits, giving approximately 5.3 × 10^36 possible values — making collisions virtually impossible.

When to Use UUIDs

UUIDs are used as database primary keys (especially in distributed systems), API resource identifiers, session tokens, file names, message queue IDs, and anywhere you need a unique identifier without coordination between systems. UUID v4 is recommended for most use cases due to its simplicity and randomness.

Common Use Cases

  • Database primary keys (PostgreSQL, MongoDB)
  • API resource identifiers
  • Distributed system node IDs
  • Session and correlation IDs
  • File and object naming
  • Message queue deduplication