UUID v4 is a randomly generated universally unique identifier in the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. The "4" indicates version 4, and the high bits of the third group indicate the variant. It has 122 bits of randomness.

How random are these UUIDs?

They use crypto.randomUUID() which is backed by the operating system's cryptographically secure random number generator (CSPRNG) — the same source used for cryptographic keys.

What is the difference between a UUID and a GUID?

Functionally the same. GUID (Globally Unique Identifier) is Microsoft's term for UUID. Both follow the same RFC 4122 standard.

Can I generate UUIDs without hyphens?

Yes. Toggle the "Remove hyphens" option to generate compact 32-character hex strings without the standard hyphen separators.

UUID Generator

Generates RFC 4122 version 4 (random) UUIDs using the browser's cryptographically secure `crypto.randomUUID()` API. Choose the number to generate (1–100), uppercase or lowercase output, and whether to include hyphens. UUIDs are used as unique database record identifiers, session tokens, correlation IDs, and file names.

Count

UppercaseInclude hyphens

Generate any number of cryptographically random UUIDs in the format your project requires.

Frequently Asked Questions

Related Tools

Diff Checker

Compare two blocks of text and highlight the differences.

Regex Tester

Test regular expressions against sample text with live match highlighting.

Character Counter

Count characters against Twitter, LinkedIn, and SMS limits.