UUID Generator
Generate random UUIDs (v4) instantly. Bulk generate up to 50 at once.
912038e9-6ae1-41ae-b489-94329cd1abe6What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify resources in computer systems. Also known as a GUID (Globally Unique Identifier), UUIDs are designed to be unique across space and time without requiring a central authority.
UUID versions compared
| Version | Based On | Use Case |
|---|---|---|
| v1 | Timestamp + MAC address | Time-ordered records |
| v4 | Random numbers | General purpose (most common) |
| v5 | SHA-1 hash of namespace + name | Deterministic IDs from input |
| v7 | Unix timestamp + random | Sortable, database-friendly |
Frequently Asked Questions
Can two UUIDs be the same?
Technically possible but astronomically unlikely. A v4 UUID has 2^122 possible values (about 5.3 x 10^36). You would need to generate 1 billion UUIDs per second for 100 years to have a 50% chance of a single collision.
What is the format of a UUID?
A standard UUID is a 36-character string formatted as 8-4-4-4-12 hexadecimal digits:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. The version number appears in the third group (e.g., 4xxx for v4).
Should I use UUID v4 or v7?
Use v4 for general-purpose random IDs. Use v7 if you need time-sortable IDs (e.g., database primary keys) — v7 UUIDs sort chronologically while remaining globally unique.