What is a version-4 UUID?

A v4 UUID is a 128-bit identifier generated from random data, written as 32 hex digits in five groups, like 550e8400-e29b-41d4-a716-446655440000.

Are these UUIDs unique?

For all practical purposes, yes. With around 122 random bits, the chance of generating two identical UUIDs is negligibly small.

Yes. They use your browser's cryptographically secure random generator and are never sent anywhere.

Generators

Generate random v4 UUIDs in bulk.

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How many

Generate random version-4 UUIDs (also called GUIDs) in bulk, ideal for database keys, test data and API identifiers.

Create up to 100 at once and copy them all with a single click.

Version-4 UUIDs are built from random data, giving about 122 bits of randomness, which makes accidental collisions practically impossible.

Generate a UUID v4

Input: Generate 1 identifier

Output: A random UUID such as 3f2504e0-4f89-41d3-9a0c-0305e82c3301

Each run produces a different RFC 4122 version 4 identifier.

What is a version-4 UUID?: A v4 UUID is a 128-bit identifier generated from random data, written as 32 hex digits in five groups, like 550e8400-e29b-41d4-a716-446655440000.
Are these UUIDs unique?: For all practical purposes, yes. With around 122 random bits, the chance of generating two identical UUIDs is negligibly small.
Are they generated securely?: Yes. They use your browser's cryptographically secure random generator and are never sent anywhere.

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