UUID Generator

Generate RFC 4122 compliant UUIDs instantly — v4 (random) and v1 (timestamp-based)
550e8400-e29b-41d4-a716-446655440000

Generator Options

v4: Cryptographically random — best for most use cases

Validate UUID

Client-Side Only • No Rate Limits • No Signup Required

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. Unlike sequential IDs, UUIDs can be generated independently without coordination, making them perfect for distributed systems, databases, and APIs.

UUIDs are standardized by RFC 4122 and are represented as 32 hexadecimal digits displayed in 5 groups separated by hyphens:

xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx

Where M indicates the UUID version (1-8) and N indicates the variant.

UUID Versions Explained

UUID v4 (Random)

Version 4 UUIDs are generated using random numbers. They provide the strongest uniqueness guarantees with 2^122 possible combinations — so many that the chance of collision is effectively zero for any practical application.

  • Best for: Most applications, databases, APIs, session tokens
  • Example: f47ac10b-58cc-4372-a567-0e02b2c3d479
  • Uniqueness: 2^122 possible values

UUID v1 (Timestamp-based)

Version 1 UUIDs combine a timestamp (60 bits), a clock sequence (14 bits), and a node ID (48 bits, typically MAC address). They're not completely random but provide uniqueness through time and space.

  • Best for: Ordered IDs, when you need to know when a UUID was created
  • Example: a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11
  • Note: Contains timestamp information (not anonymous)

Common UUID Formats

Format Example Usage
Standard 550e8400-e29b-41d4-a716-446655440000 Most common, used everywhere
Braces {550e8400-e29b-41d4-a716-446655440000} Windows registry, some Microsoft tools
URN urn:uuid:550e8400-e29b-41d4-a716-446655440000 RFC 4122 URN namespace
No hyphens 550e8400e29b41d4a716446655440000 Compact storage, some databases

How to Use This Tool

  1. Choose your version — Select v4 for random UUIDs (recommended) or v1 for timestamp-based UUIDs.
  2. Pick your format — Standard with hyphens is most common, but choose braces or URN format if needed.
  3. Set case preference — Lowercase is standard, but some systems prefer uppercase.
  4. Set quantity — Need just one? Leave it at 1. Need thousands? Adjust the slider up to 10,000.
  5. Generate — Click the button or use the refresh icon for instant results.
  6. Copy or export — Copy individual UUIDs or export bulk results as CSV, JSON, or TXT.

Common Use Cases

  • Database primary keys — Distributed systems can generate IDs without conflicts
  • API resource identifiers — REST APIs use UUIDs to identify resources
  • Session tokens — Secure, unguessable tokens for user sessions
  • File names — Unique names for uploaded files to prevent collisions
  • Test data — Generate realistic IDs for development and testing
  • Transaction IDs — Unique identifiers for financial transactions

Frequently Asked Questions

What is a UUID?
UUID stands for Universally Unique Identifier. It's a 128-bit number used to identify information in computer systems. UUIDs are designed to be unique across both space and time, making them ideal for distributed systems.
What's the difference between UUID v4 and v1?
UUID v4 is randomly generated and provides the strongest uniqueness guarantees. UUID v1 is based on the current timestamp and the MAC address of the generating computer, making it slightly less random but traceable to when and where it was created.
Are these UUIDs truly unique?
UUID v4 has approximately 2^122 possible values, making the chance of collision astronomically small. For practical purposes, you can treat them as unique. UUID v1 includes timestamp and node information, further reducing collision chances.
Is this tool free to use?
Yes, completely free. No signup required, no rate limits, no data stored. Generate as many UUIDs as you need.
Can I generate UUIDs in bulk?
Absolutely. You can generate up to 10,000 UUIDs at once. Use the quantity slider or enter a specific number, then export the results as CSV, JSON, or plain text.
How do I validate a UUID?
Use our built-in UUID validator. Paste any UUID into the validator field, and we'll check if it conforms to the RFC 4122 standard and identify which version it is.