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UUID Generator

Generate random UUID (Universally Unique Identifier) v4 values using your browser crypto API. Generate in bulk and copy all at once.

Number of UUIDs1
150
VersionUUID v4 (random)
Bits of randomness122 bits
Collision probability1 in 5.3 × 10³¶
Format8-4-4-4-12 hex characters
Frequently Asked Questions
What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify objects or records in software systems. It is typically displayed as 32 hexadecimal digits in the format 8-4-4-4-12.

What is UUID v4?

UUID v4 is generated using random or pseudo-random numbers. It has 122 bits of randomness, making collisions extremely unlikely. It is the most common UUID type used in modern applications.

What is the difference between UUID and GUID?

UUID and GUID (Globally Unique Identifier) are the same thing. GUID is Microsoft's implementation of UUID. Both use the same format and are interchangeable.

How do I generate a UUID in my code?

In JavaScript: crypto.randomUUID(). In Python: import uuid; uuid.uuid4(). In Java: UUID.randomUUID(). In C#: Guid.NewGuid(). This online generator uses the browser crypto API, which is the same source of randomness.

Can two UUIDs ever be the same?

The probability of generating a duplicate UUID v4 is 1 in 5.3 × 10^36. In practice, with billions of UUIDs generated per day, duplicates are theoretically possible but have never been observed in practice.

When should I use a UUID instead of an auto-increment integer?

Use UUIDs when: you generate IDs across multiple systems or databases, you need IDs before inserting into a database, you want to avoid exposing sequential record counts, or you are building distributed systems.

What does UUID stand for?

UUID stands for Universally Unique Identifier. The standard is defined in RFC 4122 by the IETF.