UUID / GUID Generator

A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. It is written as 32 hexadecimal digits grouped into five segments separated by hyphens, like 550e8400-e29b-41d4-a716-446655440000. UUIDs are designed to be globally unique without requiring a central authority to assign them.

There is no technical difference. GUID (Globally Unique Identifier) is Microsoft's name for the same concept as UUID (Universally Unique Identifier), defined in RFC 4122. Both are 128-bit identifiers formatted the same way. In most contexts the terms are interchangeable.

UUID v4 is the most common version. It is generated using random numbers. The version and variant bits are fixed so parsers can identify it, but the remaining 122 bits come from a cryptographically secure random number generator (or Math.random as a fallback), making collisions statistically impossible for practical purposes.

UUID v1 is generated from a timestamp (the number of 100-nanosecond intervals since October 15, 1582) plus a random or pseudo-random node identifier (often the MAC address). It encodes when the UUID was created, which can be useful for sorting but leaks timing information. Most modern systems prefer v4 for privacy.

Yes. This tool uses crypto.getRandomValues() — a cryptographically strong random number generator built into modern browsers. If that API is unavailable, it falls back to Math.random() (non-cryptographic). All generation happens locally in your browser; no data is sent to any server.

Use the formatting options: 'No hyphens' removes dashes for systems that store raw hex. 'Braces' adds {curly braces} for COM/.NET GUID literals. 'URN prefix' adds urn:uuid: for semantic-web or XML contexts. 'UPPERCASE' switches to all-caps, which some databases prefer.

With properly random v4 UUIDs, the probability of generating a duplicate among 2.71 quintillion UUIDs is roughly 50%. For all practical purposes — generating thousands, millions, or even billions — the chance of a collision is effectively zero. This is why UUIDs are trusted as unique identifiers without a central registry.

No. UUID generation and validation happen entirely in your browser. No text, generated identifiers, or usage data is transmitted, logged, or stored on any server. You can safely generate UUIDs for sensitive systems.

Yes. Use the UUID v4 tab and click Generate Bulk. You can generate up to 1,000 UUIDs in a single batch. Results can be copied as a list or downloaded as a .txt file.

The validator checks the syntax of a pasted identifier, removes optional braces or URN prefixes, verifies the 32-hex-character structure (with or without hyphens), and inspects the version and variant nibbles to report the UUID version and variant type.