UUID

Generate random Universally Unique IDentifiers (UUID) that match the RFC4122 specification.

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier that is designed to be unique across all space and time. UUIDs are standardized by the RFC 4122 specification and are commonly used in software development to identify resources without requiring a central authority to coordinate ID assignment.

A typical UUID looks like this: 550e8400-e29b-41d4-a716-446655440000. The format consists of 32 hexadecimal digits displayed in five groups separated by hyphens, in the form 8-4-4-4-12.

Why Generate UUIDs Client-Side?

Our UUID generator runs entirely in your browser using JavaScript's cryptographically secure random number generator. This means:

• Complete Privacy: Your generated UUIDs never leave your device—we don't see them, store them, or log them.
• No Network Required: Once the page loads, you can generate UUIDs even while offline.
• Instant Generation: No server round-trip means UUIDs are generated instantaneously.
• Cryptographically Secure: We use the Web Crypto API for random number generation, ensuring high-quality randomness.

UUID Versions Explained

Different UUID versions serve different purposes. Here's when to use each:

• UUID v1: Time-based UUID using timestamp and MAC address. Useful when you need sortable IDs and don't mind exposing generation time.
• UUID v4: Randomly generated UUID. The most commonly used version—perfect for general-purpose unique identifiers where privacy matters.
• UUID v6: Reordered time-based UUID. Like v1 but with improved database indexing performance due to better sorting characteristics.
• UUID v7: Unix timestamp-based UUID. The newest version, designed for modern distributed systems with excellent sortability and database performance.

Common Use Cases

• Database Primary Keys: UUIDs make excellent primary keys, especially in distributed databases where auto-incrementing IDs could conflict.
• API Resource Identifiers: Use UUIDs in REST APIs to identify resources without exposing internal database IDs.
• Session Tokens: Generate unique session identifiers for user authentication.
• File Names: Create unique file names for uploads to prevent naming collisions.
• Distributed Systems: Generate IDs across multiple servers without coordination or collision risk.

UUID vs GUID

You may see the term GUID (Globally Unique Identifier) used interchangeably with UUID. While Microsoft coined the term GUID, they are functionally identical to UUIDs. Both refer to 128-bit identifiers following the same format and generation algorithms.