Free Online UUID Generator
Generate random version 4 UUIDs (GUIDs) instantly and in bulk, right in your browser.
How many UUIDs?
Generated UUIDs
About the UUID Generator
This tool generates RFC 4122 version 4 UUIDs (also called GUIDs) using your browser's cryptographically secure random number generator. Generate a single UUID instantly, or create up to 100 at once for seeding databases, test fixtures, or unique identifiers in code.
Features:
- Cryptographically secure UUID v4 generation via crypto.randomUUID()
- Generate 1 to 100 UUIDs at once
- Optional uppercase, no-hyphens, or quoted list-ready formatting
- One-click copy for a single UUID or the entire list
How to Generate a UUID
- A UUID is generated automatically as soon as the page loads.
- Set how many UUIDs you need (1–100) and any formatting options.
- Click Generate to create your list.
- Copy a single UUID or use Copy All to copy the entire list.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information without requiring a central authority to issue it. It's commonly used as a database primary key, session ID, or unique identifier in distributed systems.
Is this a version 4 (random) UUID?
Yes. Every UUID generated by this tool is a version 4 UUID, meaning it is generated using random or pseudo-random numbers via the browser's crypto.randomUUID() API, as defined in RFC 4122.
Are the UUIDs generated on my device?
Yes. Every UUID is generated locally in your browser using the Web Crypto API. Nothing is sent to a server, and no UUID is ever logged or stored.
Can two generated UUIDs ever collide?
In practice, no. A version 4 UUID has 122 random bits, giving about 5.3 × 10^36 possible values. You would need to generate roughly 2.71 quintillion UUIDs before there's a 50% chance of a single collision — a number far beyond any realistic use case.
Can I generate more than 100 UUIDs at once?
This tool limits a single batch to 100 UUIDs to keep the page fast and easy to copy. For larger batches, run the generator multiple times, or use crypto.randomUUID() directly in a script.
What's the difference between UUID and GUID?
They're effectively the same thing. GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit identifier format standardized as UUID in RFC 4122. Values generated here work as either a UUID or a GUID.
Privacy
Every UUID is generated locally in your browser. No UUID is ever sent to or stored on our servers.