Free UUID Generator Online | Generate UUID v4 in Bulk | SkyBrance

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier that is globally unique across space and time. UUIDs are standardized by RFC 4122 and are used extensively in software development for database primary keys, distributed systems, session IDs, file names, and anywhere you need a unique identifier without a central authority.

Our generator creates Version 4 UUIDs, which are randomly generated using a cryptographically secure random number generator (via the Web Crypto API). The probability of generating duplicate UUIDs is astronomically low - you would need to generate 1 billion UUIDs per second for about 85 years to have a 50% chance of a single collision.

Key Features

Cryptographically Secure

Uses the Web Crypto API (crypto.randomUUID) for true randomness.

Bulk Generation

Generate up to 100 UUIDs at once for batch operations.

Format Options

Toggle uppercase and no-dashes modes to match your project's convention.

One-Click Copy

Copy individual UUIDs or all at once. Download as a text file.

Frequently Asked Questions

What is UUID v4?

UUID v4 is a randomly generated version of UUID. It uses 122 random bits (6 bits are used for version and variant), making collisions virtually impossible. It's the most commonly used UUID version in modern applications.

Are these UUIDs truly random?

Yes. We use the browser's crypto.randomUUID() method which is backed by a cryptographically secure pseudo-random number generator (CSPRNG).

Can I use these as database primary keys?

Absolutely. UUID v4 is widely used as primary keys in PostgreSQL, MongoDB, MySQL, and other databases. They're ideal for distributed systems where auto-increment IDs would cause conflicts.

What's the difference between UUID and GUID?

They're the same thing. GUID (Globally Unique Identifier) is Microsoft's term for UUID. The format and generation methods are identical.

About the UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit value used to identify records, resources, and objects without a central coordinator. This generator produces version 4 (random) UUIDs using a cryptographically secure random source, and can generate them in bulk for seeding databases or test data.

Frequently asked questions

What is a UUID v4?

Version 4 UUIDs are generated from random numbers. The odds of two colliding are astronomically small, which is why they are widely used as primary keys and identifiers.

Are these UUIDs cryptographically random?

Yes. They are built from the Web Crypto API’s secure random generator, so they are safe to use as unpredictable identifiers.

Can I generate many UUIDs at once?

Yes. Set the count to bulk-generate UUIDs, which is handy for seeding databases or creating test fixtures.

Are UUIDs guaranteed to be unique?

They are not mathematically guaranteed, but a v4 collision is so improbable that they are treated as unique in practice.

Free Online UUID Generator