What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label, almost always written as 32 hexadecimal digits grouped as 8-4-4-4-12. The same format is often called a GUID in Microsoft ecosystems. UUIDs are designed so that independently generated values collide only with negligible probability, which makes them ideal for primary keys, request IDs, and correlation tokens in distributed systems.
Different UUID versions use different algorithms. Version 4 is random; version 7 combines a millisecond timestamp with random bits so identifiers sort roughly by creation time while staying unique.
How to Use This UUID Generator
- Choose UUID v4 for classic random IDs, or UUID v7 for time-ordered identifiers.
- Pick how many values you need (1, 5, 10, 25, or 50) and click Generate.
- Toggle uppercase hex or hyphens to match your API or database convention.
- Use Copy on a single row or Copy all to grab every value at once.
Common Use Cases
- Database primary keys: UUIDs avoid auto-increment coordination across services.
- HTTP request and trace IDs: Correlate logs across microservices.
- File and session names: Generate unique filenames or ephemeral tokens without a central allocator.
- Testing and fixtures: Quickly produce valid identifier samples for APIs and ORMs.
Privacy and Security
Generation uses the browser's Web Crypto APIs. Identifiers never leave your device unless you copy them elsewhere yourself. This tool does not store UUIDs on our servers.