Wyvek

UUID Generator

Generate random UUID / GUID v4 identifiers.

Free online UUID (v4) generator

This UUID generator creates random version 4 UUIDs — also known as GUIDs — instantly in your browser. A v4 UUID is a 128-bit identifier built almost entirely from random data, formatted as 36 characters like 3f2504e0-4f89-41d3-9a0c-0305e82c3301. Because each one carries 122 bits of randomness, you can hand out billions of them across independent systems without ever coordinating, and still trust they won't collide. Generate a single ID or up to 500 at once, then copy them all with one click.

How to generate UUIDs

  1. Enter how many UUIDs you need (from 1 up to 500).
  2. Optionally tick Uppercase for capital A–F digits.
  3. Optionally tick Remove hyphens for a compact 32-character form.
  4. Click Generate — a fresh batch appears instantly, one per line.
  5. Press Copy all to copy the whole list to your clipboard.

What are UUIDs used for?

UUIDs shine anywhere you need a unique identifier without a central authority to issue it. Common uses include database primary keys and record IDs, request or trace IDs for logging and debugging, idempotency keys for API calls, unique filenames for uploaded assets, and message IDs in distributed systems. Each identifier here is produced with your browser's cryptographically secure random generator, so it's safe to use as a key or token. If you need a one-way fingerprint of data instead of a random ID, try the hash generator, and for random secrets and login credentials use the password generator.

Private and dependency-free

Every UUID is generated locally with crypto.randomUUID() — or a standards-compliant fallback that sets the correct version and variant bits — so nothing you generate is ever uploaded or stored. There's no sign-up and no limit on how many batches you create. Bookmark this page for the next time you need quick, unique v4 identifiers.

Frequently asked questions

What is a UUID (version 4)?

A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value written as 36 characters in the form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. A version 4 UUID is generated almost entirely from random data — the "4" marks the version and the "y" digit encodes the variant. Because there are 122 random bits, the odds of two v4 UUIDs colliding are vanishingly small.

Are these UUIDs random and secure?

Yes. Each identifier is generated with your browser's cryptographically secure random number generator — crypto.randomUUID() where available, otherwise crypto.getRandomValues() with the correct version and variant bits set. Everything runs locally in your browser, so no UUID is ever transmitted to or logged by a server.

What are UUIDs commonly used for?

UUIDs are widely used as primary keys and database record IDs, request or trace IDs for logging, idempotency keys for APIs, filenames for uploaded assets, session tokens, and message identifiers in distributed systems. They let independent services create unique IDs without coordinating with a central authority.

What is the difference between a UUID and a GUID?

They are the same thing. GUID (Globally Unique Identifier) is the name Microsoft uses, while UUID is the term from the RFC 4122 / RFC 9562 standards. Both describe the same 128-bit identifier format, so a v4 UUID and a v4 GUID are interchangeable.

Can I generate UUIDs in bulk without hyphens or in uppercase?

Yes. Set how many you need (up to 500 at once), then toggle Uppercase to get A–F digits in capitals and Remove hyphens to output a compact 32-character string. This is handy when a database column, URL path, or key format expects a specific style.

Will the same UUID ever be generated twice?

In practice, no. A version 4 UUID has 122 bits of randomness, giving over 5 undecillion possible values. Even generating billions of UUIDs, the probability of a duplicate is negligibly small, which is why they are safe to use as unique keys without checking for collisions.

Password Generator Create strong, random, secure passwords. Hash Generator Generate MD5, SHA-1, and SHA-256 hashes. QR Code Generator Create QR codes for links, text, and more. Random Number Generator Generate random numbers in any range.