UUID Generator

How to Use

Select the UUID version (v4 or v7) and the number of UUIDs to generate, then click "Generate". UUIDs are automatically regenerated when you change any setting. Click a UUID to select and copy it, or use the copy button.

What Is UUID

UUID (Universally Unique Identifier) is a standard for generating unique identifiers in distributed systems. The format is "8-4-4-4-12" hexadecimal characters, totaling 36 characters (e.g., 550e8400-e29b-41d4-a716-446655440000).

UUID Versions

This tool supports UUID v4 and v7. There are several UUID versions, each with different generation strategies:

• v1: Based on timestamp and MAC address. Reveals when and where it was created.
• v4: Based on random numbers (122 bits of randomness). No information leakage. Most widely used.
• v5: Based on SHA-1 hash of a namespace and name. Deterministic — same input always produces the same UUID.
• v7: Based on Unix timestamp with random bits. Sortable by creation time. Newer standard (RFC 9562).

v4 uses crypto.randomUUID(). v7 uses crypto.getRandomValues() with an embedded timestamp. For most use cases (database keys, session IDs, API tokens), v4 is recommended. Use v7 when you need time-sortable IDs.

Privacy & Security

This tool uses the browser's built-in cryptographic APIs (crypto.randomUUID() for v4, crypto.getRandomValues() for v7). No data is ever sent to a server — all processing happens entirely in your browser.