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Universal UUID Generator

Generate secure, random v4, time-sortable v7, and namespace-based v5 UUIDs instantly. 100% client-side and private.

The Ultimate Guide to UUIDs

A Universally Unique Identifier (UUID) is a 128-bit label used for information in computer systems. Unlike traditional incremental IDs, UUIDs can be generated independently without a central authority, making them essential for distributed systems, microservices, and modern web applications.

Deep Dive into UUID Versions

UUID v1

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Generated using the current timestamp and the node (MAC address). Useful for knowing exactly when an ID was created.

UUID v4

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The most common version, generated using cryptographically strong random numbers. Collision risk is astronomically low.

UUID v7

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The modern standard for databases. Time-sortable, which significantly improves indexing performance (B-tree friendliness).

UUID v5

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Deterministic IDs generated by hashing a Namespace and a Name together. Perfect for consistent mapping.

When to use which UUID?

General Purpose

Use v4 for unique identifiers where sortability isn't required.

Databases

Use v7 for primary keys to maintain high performance during inserts and lookups.

Consistent Mapping

Use v5 when you need to generate the same ID consistently from the same input data.

Frequently Asked Questions

Statistically, yes. While not mathematically guaranteed to be unique across all time and space, the probability of generating two identical UUID v4s is so small that it's practically impossible in any real-world scenario.
GUID (Globally Unique Identifier) is Microsoft's implementation of the UUID standard. For most practical purposes, they are identical and follow the same format.
Yes, UUID v4 is generated using cryptographically secure random numbers, making it suitable for session IDs, password reset tokens, and other security-sensitive identifiers.
Standard random UUIDs (v4) cause 'index fragmentation' in databases because they are inserted in random order. UUID v7 is time-ordered, meaning new IDs are always appended to the end of the index, keeping it compact and fast.
No. UUIDs are either random (v4) or generated using one-way cryptographic hashes (v5). You cannot 'decrypt' a UUID to find the original name or namespace used to create it.