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

Free Online UUID v3 Generator - MD5 Name-based Tool

Generate UUID v3 online for free. This browser-based tool creates deterministic UUIDs by MD5-hashing namespace and name - same input always produces the same UUID. No installation needed.

When to Use This Version

Use UUID v3 when you need reproducible IDs from input data - URL-to-UUID mapping, content-addressable storage, cache keys, or deduplication systems. Same input always equals same output, enabling distributed systems to generate identical IDs independently.

Best Practices

For new projects, prefer v5 (SHA-1) over v3 (MD5) for better hash strength. Use standard namespaces (DNS, URL, OID, X.500) when applicable, or create a custom namespace UUID for your application. Remember: v3/v5 are not encryption - anyone with the namespace and name can reproduce the UUID.

Compare with Other Versions

v4 Random
v7 Unix Time
GUID
View All UUID Versions

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UUID Version 3 Questions

UUID v3 is a name-based identifier created by MD5-hashing a namespace UUID and a name string. The same namespace + name always produces the same UUID - it's deterministic.

Use v3 when you need reproducible IDs from names. URL-to-UUID mapping, content addressing, deduplication. Same input = same output, every time. Consider v5 (SHA-1) for better hash strength.

Standard namespaces: DNS (6ba7b810-...), URL (6ba7b811-...), OID (6ba7b812-...), X.500 DN (6ba7b814-...). You can also create custom namespace UUIDs for your application.

MD5 has known collision vulnerabilities, but for UUID generation (not cryptographic security) it's generally fine. If you're paranoid, use v5 (SHA-1) instead. Neither is for encryption - they're for consistent ID generation.