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UUID Generator

Generate Universally Unique Identifiers (UUIDs) for your applications

About UUIDs

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit label used for information in computer systems. UUIDs are designed to be unique across both space and time, making them ideal for identifying resources in distributed systems without central coordination.

UUID Format

A standard UUID is represented as a 32-character hexadecimal string, divided into five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 hexadecimal characters and 4 hyphens).

Example: 550e8400-e29b-41d4-a716-446655440000

UUID Versions

  • Version 1 (Time-based): Generated using the current timestamp and the MAC address of the computer. While this ensures uniqueness, it may raise privacy concerns as the MAC address can be extracted from the UUID.
  • Version 4 (Random): Generated using random or pseudo-random numbers. This is the most commonly used version as it provides a good balance between uniqueness and privacy.
  • Version 5 (Name-based, SHA-1): Generated by hashing a namespace identifier and name. This produces consistent UUIDs for the same inputs.

Applications of UUIDs

  • Database keys: UUIDs are often used as primary keys in databases, especially in distributed systems where multiple servers might be generating records simultaneously.
  • Session IDs: Web applications use UUIDs to track user sessions securely.
  • Transaction IDs: UUIDs can uniquely identify transactions in financial systems.
  • Device identification: UUIDs are used to uniquely identify devices in networks.
  • Content addressing: UUIDs can be used to reference content regardless of its location.

Advantages of UUIDs

  • Uniqueness: The probability of a UUID collision is extremely low, making them suitable for distributed systems without central coordination.
  • No central authority: UUIDs can be generated independently without the need for a central issuing authority.
  • Standardization: UUIDs follow established standards (RFC 4122), ensuring compatibility across different systems.