UUID Generator

Why Use Our UUID Generator?

• Fast and Secure: Generate UUIDs instantly in your browser using the Web Crypto API. No data is sent to external servers, ensuring complete privacy.
• Bulk Generation: Need hundreds of UUIDs for database seeding or testing? Generate up to 500 at once with a single click.
• Customizable Output: Choose between uppercase or lowercase, and include or remove hyphens based on your specific formatting needs.
• Multiple Versions: Support for both time-based (v1) and random (v4) UUIDs.

What is a UUID?

A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value written as 32 hexadecimal digits in five groups, such as 123e4567-e89b-42d3-a456-426614174000. UUIDs can be generated independently on any machine with practically no chance of two being the same, which is why they're used as database keys, request IDs and file names without a central counter.

Version 4 vs version 1

Version 4 UUIDs are built from 122 random bits. They reveal nothing about when or where they were created, and they're the right default for most applications. Version 1 UUIDs combine a timestamp with a node identifier, so they sort roughly by creation time but can leak when an ID was generated. If you need time-ordered IDs for database indexes, consider version 7, which is designed for that purpose.

Can two UUIDs collide?

In theory yes, in practice no. With 2¹²² possible v4 values, you would need to generate about 2.7 quintillion UUIDs before the chance of a single duplicate reaches 50%. The real risk is a weak random number generator, which is why this tool uses the browser's cryptographically secure Web Crypto API.

Learn more in our guide: What is a UUID and how does it work?