UUID/GUID Generator

UUID Version Selection

Generated UUIDs

UUID Decoder & Validator

UUID Version Info

Version 4 - Random

Randomly generated UUID with 122 bits of randomness. Most commonly used version for general purposes.

UUID Structure

Standard UUID format:

xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
  • M: Version digit (1-7)
  • N: Variant bits (8, 9, A, or B)
  • Total: 128 bits / 32 hex digits
Common Use Cases
  • 🗄️ Database Primary Keys
  • 📡 API Resource IDs
  • 🔗 Unique Identifiers
  • 📊 Distributed Systems
  • 🔄 Message IDs
Quick Actions

Professional UUID/GUID Generator for All Versions

Generate universally unique identifiers (UUIDs) and globally unique identifiers (GUIDs) across all standard versions. Our comprehensive tool supports UUID versions 1, 2, 3, 4, 5, 6, and 7 with validation, decoding, and formatting options.

UUID Version Overview

  • Version 1: Time-based UUIDs using MAC address and timestamp
  • Version 2: DCE Security UUIDs with embedded POSIX UID/GID (rarely used)
  • Version 3: Name-based UUIDs using MD5 hashing
  • Version 4: Random UUIDs (most common) with 122 random bits
  • Version 5: Name-based UUIDs using SHA-1 hashing
  • Version 6: Reordered time-based UUIDs for better sorting
  • Version 7: Unix Epoch time-based UUIDs

UUID Applications in Development

  • Database primary keys and foreign key relationships
  • RESTful API resource identification
  • Distributed system entity tracking
  • Session management and authentication tokens
  • Message queue and event identification
  • Microservice communication and data correlation

UUID vs GUID

UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) refer to the same 128-bit concept. GUID is Microsoft's term with uppercase formatting and optional braces, while UUID is the RFC 4122 standard. Our generator supports both formats.

Best Practices for UUID Usage

  • Use Version 4 for general-purpose unique identifiers
  • Consider Version 7 for time-ordered requirements
  • Store UUIDs in binary format for database efficiency
  • Use uppercase format for consistency in APIs
  • Always validate UUID format before processing

UUID Questions

It's a 128-bit ID designed to be unique without needing a central server to hand them out. Database primary keys, API resource IDs, session tokens — anywhere you need "this will never collide" confidence.

v1 = timestamp + MAC address (reveals machine info). v3/v5 = hash a name to always get the same ID. v4 = pure random (most common). v6/v7 = timestamp-based but sortable. Pick based on whether you need randomness, determinism, or time-ordering.

v4 for 90% of cases — it's random, simple, and universally supported. v7 if you want IDs that sort chronologically (helps with database indexing). v5 if you need the same input to always produce the same UUID.

With v4, you'd need to generate about 103 trillion UUIDs to hit a 50% collision chance. For perspective, that's more than generating 1 billion UUIDs per second for 3 years. So... no.

Only from v1, v6, or v7 — those embed time data. v4 is pure random, so there's nothing to extract. The decoder here handles time-based versions automatically.