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Tool Huddle

Generator

UUID Generator

Generate universally unique identifiers (UUIDs) in various formats. Choose from v1, v4, or v5.

Configuration

Random (most common)

Generate 1-100 UUIDs at once

No UUIDs generated yet

Configure your options above and click “Generate UUIDs” to create unique identifiers.

Generated Locally

All UUIDs are generated in your browser. Nothing is stored or transmitted.

Frequently Asked Questions

What is a UUID?

UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. UUIDs are standardized by RFC 4122 and displayed as 32 hexadecimal digits separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). They are designed to be unique across space and time without requiring a central registration authority, making them ideal for distributed systems, database primary keys, and API identifiers.

What's the difference between UUID v1, v4, and v5?

UUID v1 is time-based and includes the MAC address and timestamp—predictable but sortable. UUID v4 is randomly generated using cryptographic randomness— most common for general use with 122 random bits. UUID v5 is name-based using SHA-1 hashing—deterministic (same input = same UUID), useful for deriving UUIDs from namespaces and names. For most applications, v4 is recommended due to its simplicity and strong randomness guarantees.

Is UUID generation secure?

UUID v4 generation is cryptographically secure when using proper random number generators. Our tool uses the browser's crypto.getRandomValues() API, which provides cryptographically strong random values suitable for security-sensitive applications. UUID v1 may expose MAC addresses and should be avoided in privacy-sensitive contexts. While UUIDs are statistically unique, they should not be used as secrets or passwords—use proper authentication tokens instead.

When should I use UUIDs instead of auto-increment IDs?

Use UUIDs when you need globally unique identifiers across distributed systems, want to generate IDs client-side before server insertion, need to merge data from multiple databases, or want to hide the total count of records. Use auto-increment integers when you need sequential ordering, smaller storage footprint (4-8 bytes vs 16 bytes), faster database indexing, or human-readable IDs. Many systems use both—UUID as the public identifier and auto-increment for internal indexing.

What is the UUID format explained?

A UUID is formatted as 8-4-4-4-12 hexadecimal digits: xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx. The M digit indicates the version (1, 4, or 5). The N digit indicates the variant (usually 8, 9, a, or b for RFC 4122). For UUID v4, most digits are random except for the version and variant bits. UUIDs can be represented with or without hyphens, in uppercase or lowercase—all formats are equivalent and represent the same 128-bit value.