GUID / UUID Generator Generate Unique Identifiers Online

Generate unique GUIDs and UUIDs instantly with support for all major UUID versions. Perfect for developers, databases, and any application requiring unique identifiers.

UUID v1 (Time-based)
UUID v3/v5 (Name-based)
UUID v4 (Random)
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Understanding GUIDs and UUIDs

What is a UUID?

A Universally Unique Identifier (UUID) is a 128-bit number used to uniquely identify information in computer systems. UUIDs are designed to be unique across space and time, making them ideal for distributed systems and databases.

UUID vs GUID

GUID (Globally Unique Identifier) is Microsoft's implementation of the UUID standard. While they are technically the same, GUID is primarily used in Microsoft technologies while UUID is more universally recognized across different platforms.

UUID Versions Explained

v4 UUID Version 4 (Random)

Most commonly used version. Generated using random or pseudo-random numbers. Provides the highest entropy and uniqueness guarantee.

v1 UUID Version 1 (Time-based)

Based on timestamp and MAC address. Guarantees uniqueness across time but may reveal system information.

v3 UUID Version 3 (MD5 Hash)

Generated from a name and namespace using MD5 hashing. Deterministic - same input always produces same UUID.

v5 UUID Version 5 (SHA-1 Hash)

Similar to v3 but uses SHA-1 hashing for better collision resistance. Recommended over v3 for new implementations.

When to Use UUIDs

Database Keys

Perfect for primary keys in distributed databases

API Resources

Unique identifiers for REST API endpoints

File Systems

Avoiding naming conflicts in distributed systems