UUID Generator (GUID v4 & v7)

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What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in software systems. It is commonly used in databases, distributed systems, and web applications to avoid ID collisions.

How this UUID generator works

This tool generates UUID identifiers using modern, standards-compliant methods. UUID v4 values are produced using the browser’s cryptographically secure random number generator (Web Crypto API), while UUID v7 values combine a timestamp with secure randomness for time-ordered output.

Unlike simple pseudo-random implementations, this approach relies on operating system entropy sources, making collisions practically negligible in real-world applications.

UUID v4 vs UUID v7

This tool supports both UUID v4 (random) and UUID v7 (time-ordered) generation. While UUID v4 is the most widely used format, UUID v7 is a newer standard designed for better performance in modern systems.

UUID v4 (random) — generated using cryptographically secure randomness. Ideal for general-purpose use, tokens, and distributed systems where ordering is not required.
UUID v7 (time-ordered) — combines a timestamp with random data. This allows generated IDs to be naturally sorted by creation time, improving database indexing and write performance.

UUID v7 is especially useful in systems where large numbers of identifiers are generated and stored sequentially, such as databases, logs, and event-driven architectures.

In this tool, UUID v7 generation also uses a monotonic sequence within the same millisecond, ensuring that identifiers remain strictly ordered even when generated in rapid succession.

Generation status indicator

This tool displays how each UUID was generated by showing its version, source, and reliability level. This helps you understand the quality of the randomness used, without affecting the UUID format itself.

Version (v4 / v7) — indicates the UUID format. v4 is fully random, while v7 is time-ordered and optimized for modern systems.
Source — shows the underlying generation method:
- native — generated using crypto.randomUUID()
- secure — generated using crypto.getRandomValues()
- weak — generated using Math.random() (fallback)
Reliability — reflects the cryptographic strength of the randomness source:
- 🔐 Native secure — browser-native cryptographic generation (crypto.randomUUID())
- 🔵 Secure — Web Crypto API randomness (crypto.getRandomValues())
- ⚠️ Weak — non-cryptographic pseudo-random fallback (Math.random)

Why use this UUID generator?

Generate random UUIDs (v4) instantly
Generate multiple UUIDs at once
Export in different formats (JSON, comma-separated, newline)
Customize output (uppercase, lowercase, braces, no hyphens)

Common use cases

Database primary keys
API request identifiers
Session tokens
Distributed systems and microservices