UUID Generator

UUID Generator — Create Universally Unique Identifiers

A UUID (Universally Unique Identifier) is a 32-character hexadecimal string separated by hyphens, used to uniquely identify entities in databases, distributed systems, and APIs without a central coordinator.

UUID Versions

• v4 (random): most commonly used — generated randomly using cryptographically secure pseudo-random numbers. Collision probability is astronomically low
• v1 (time-based): derived from timestamp + device identifier, guarantees chronological ordering when sorted
• v5 (name-based): deterministically generated from namespace + name using SHA-1. Same inputs always produce the same UUID

Format Options

• Uppercase: converts letters to uppercase, e.g., 550E8400-E29B...
• No hyphens: removes dashes for a clean 32-character string
• Braces {}: wraps the UUID in curly braces as used in .NET/C#

When to Use UUIDs

• Primary keys for database records
• Session tokens in web applications
• API request identifiers for tracing
• Temporary file naming to avoid conflicts
• Message and event IDs in distributed systems