UUID3 Generator

Generate name-based UUIDs using MD5 hashing

UUID3

Click 'Generate' to create your first UUID3

About UUID3 Generator

UUID3 (Universally Unique Identifier version 3) generates deterministic identifiers using MD5 hashing with namespace and name inputs. This version creates reproducible UUIDs that remain consistent for the same input values, making it ideal for content-based identification systems.

Generate UUID3 identifiers with MD5-based hashing that produces identical results for the same namespace and name combination. The tool supports custom namespace values and accepts any text input for name generation, ensuring reproducible and verifiable identifier creation.

Perfect for content-based caching systems, data deduplication, legacy system integration, and applications requiring deterministic identifier generation. Ideal for URL shortening services, content addressing, and distributed systems where predictable UUIDs are beneficial.

UUID3 provides deterministic generation that enables consistent identifier creation across different systems and time periods. The reproducible nature makes it excellent for caching, data verification, and systems requiring predictable unique identifiers.

Key Features

  • Deterministic MD5-based generation
  • Namespace and name input support
  • Reproducible identical results
  • Content-based identification
  • Legacy compatibility
  • Predictable UUID creation

UUID3 Frequently Asked Questions

What makes UUID3 different from other UUID versions?

UUID3 is deterministic and uses MD5 hashing with namespace and name inputs. Unlike UUID4 (random) or UUID1 (time-based), UUID3 always generates the same identifier for the same input combination.

When should I use UUID3 instead of UUID4?

Use UUID3 when you need reproducible identifiers for content-based systems, caching, or when the same input should always produce the same UUID. Use UUID4 for general-purpose unique identifiers.

Are UUID3 identifiers secure?

UUID3 uses MD5 hashing, which is considered cryptographically weak. While suitable for identifier generation, avoid UUID3 for security-sensitive applications. Consider UUID5 (SHA-1) for better security.

What is a namespace in UUID3?

A namespace is a UUID that helps categorize and scope your generated identifiers. It ensures that the same name in different namespaces produces different UUIDs, preventing collisions across different contexts.

Can I predict UUID3 values?

Yes, UUID3 is deterministic. If you know the namespace and name inputs, you can predict the resulting UUID. This predictability is both a feature (for caching) and a limitation (for security).

UUID3 Best Practices

  • Use meaningful namespaces to organize your identifiers
  • Consider UUID5 for better cryptographic security
  • Document your namespace choices for future reference
  • Avoid exposing sensitive data in name inputs
  • Test deterministic behavior in your applications

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