Free UUID Generator - Create Unique Identifiers Online

Generate unique UUIDs (v1 & v4) with customizable formatting options for databases and APIs

How to Use the UUID Generator

1

Select Version

Choose between UUID v4 (random) or v1 (time-based) format.

2

Configure Options

Set quantity (1-100), format (uppercase/lowercase), and hyphens.

3

Generate & Copy

Click generate and copy individual or all UUIDs to clipboard.

What is a UUID Generator?

UUID Generator is your comprehensive solution for creating unique identifiers that are guaranteed to be unique across space and time. Whether you're working with databases, APIs, or distributed systems, our tool provides both UUID v1 (time-based) and v4 (random) formats with customizable options.

Generate single UUIDs or bulk quantities up to 100 at once, with options for uppercase/lowercase formatting and hyphen inclusion. All generation happens locally in your browser for maximum privacy and security.

Perfect for developers, database administrators, and anyone needing reliable unique identifiers for their applications, systems, or data structures.

How UUID Generation Works

UUIDs (Universally Unique Identifiers) are 128-bit numbers designed to be unique without requiring a central registration authority. Our generator creates RFC 4122 compliant UUIDs using cryptographically secure random number generation.

The standard UUID format consists of 32 hexadecimal digits arranged in five groups separated by hyphens: 8-4-4-4-12. This format ensures compatibility across different systems and programming languages.

UUID Structure

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
xxxxxxxx: 8 hex digits (time/node based)
xxxx: 4 hex digits (version/time based)
4xxx: 4 hex digits (version 4 + random)
yxxx: 4 hex digits (variant + random)
xxxxxxxxxxxx: 12 hex digits (node/random)

UUID Versions Explained

Our generator supports the two most commonly used UUID versions, each with distinct characteristics and use cases.

UUID v4 (Random)

  • Generated using random or pseudo-random numbers
  • Most commonly used version (RFC 4122)
  • 122 bits of randomness
  • Extremely low collision probability
  • Best for general-purpose use

UUID v1 (Time-based)

  • Generated using timestamp and MAC address
  • Embeds creation time in the UUID
  • Naturally sortable by creation time
  • Useful for ordered data
  • May reveal machine identity

Common UUID Use Cases

Database Primary Keys

Use UUIDs as primary keys for distributed databases where auto-increment IDs aren't suitable.

API Request IDs

Track API requests and responses with unique identifiers for logging and debugging.

File Naming

Generate unique filenames for uploads to prevent conflicts and ensure uniqueness.

Session Management

Create unique session tokens and identifiers for user authentication systems.

Message Queue IDs

Identify messages in distributed systems and message queues uniquely.

Resource Identifiers

Generate unique IDs for resources in microservices and distributed applications.

Frequently Asked Questions

UUID v1 is time-based and includes timestamp information, making it sortable. UUID v4 is completely random and provides maximum uniqueness with no predictable patterns.

UUIDs are designed to be unique across space and time. The probability of generating two identical UUIDs is extremely low - about 1 in 2^128, or roughly 1 in 340 undecillion.

Use UUID v1 when you need sortable IDs or want to embed timestamp information. Use UUID v4 for general purposes where maximum randomness and unpredictability are desired.

UUID v4 provides good randomness and is suitable for most security applications. However, UUID v1 may leak timestamp information, so v4 is generally preferred for security-sensitive uses.

Yes, this tool generates UUIDs entirely in your browser using JavaScript. No data is sent to any server - all generation happens locally for maximum privacy.

The standard format is 8-4-4-4-12 hexadecimal digits separated by hyphens, totaling 36 characters. For example: 550e8400-e29b-41d4-a716-446655440000