GUID generator
Generate v4 GUIDs / UUIDs using the browser's cryptographic random source.
Runs 100% in your browserHow to generate GUIDs
- Pick a count. Generate 1 to 1,000 at a time.
- Format. Toggle braces, upper-case or no hyphens.
- Copy or download. Output as plain text — one per line.
GUID and UUID — the same thing
The Microsoft ecosystem calls them GUIDs; the IETF calls them UUIDs. They are the same 128-bit
identifier in the same byte layout, just with different naming preferences. Version 4 is the
only flavour you can produce without external context — a clock or a hardware address — and the
browser's crypto.randomUUID() uses cryptographically secure randomness, so v4 IDs
generated here are suitable for security-sensitive use.
Frequently asked questions
- Yes — different names for the same 128-bit identifier. Microsoft uses "GUID" (Globally Unique Identifier); the IETF spec calls it "UUID" (Universally Unique Identifier, RFC 4122). The byte layout is identical.
- Version 4 (random), the most common and the only one you can generate without a clock or a MAC address. Cryptographically random via the browser's WebCrypto.
- A v4 has 122 bits of randomness — the collision probability for a billion GUIDs is on the order of 10⁻¹⁸. Effectively unique for any application scale.
- Lower-case canonical form 8-4-4-4-12 hex. Use the wrap toggle to add curly braces, the Windows registry style.