UUID Generator
Generate 1 to 1000 random version-4 UUIDs instantly. Options for uppercase and no-hyphen formats, with one-click copy of the full list.
About the UUID Generator
This UUID generator creates version-4 (random) UUIDs using your browser's cryptographically secure random number generator — the same crypto.randomUUID() API used in production code. Generate a single identifier or up to 1,000 at once for seeding databases, test fixtures and CSV imports.
Two formatting options cover the common variants: uppercase output for systems that store GUIDs in capitals (like older Microsoft tooling), and hyphen-free output for databases or URLs where the 32-character compact form is preferred. The underlying random values stay the same when you toggle options, so you can copy both representations of the same ID.
Every UUID is generated locally on your device and never transmitted, and the Regenerate button gives you a fresh batch instantly.
How to Use the UUID Generator
- 1Choose how many UUIDs you need (1–1000).
- 2Toggle uppercase or remove-hyphens if your system needs those formats.
- 3Click Regenerate for a fresh batch.
- 4Copy the whole list with one click.
Frequently Asked Questions
What is a version 4 UUID?
A version-4 UUID is a 128-bit identifier where 122 bits are random; the remaining 6 bits mark the version (4) and variant. Written as 36 characters (32 hex digits plus 4 hyphens), an example is 3f9a2d7e-8b1c-4e5f-9a2b-1c3d4e5f6a7b. Because the randomness space is astronomically large, v4 UUIDs are generated independently with no coordination and no meaningful collision risk.
Are these UUIDs cryptographically secure and unique?
They are generated with crypto.randomUUID(), which draws from the browser's cryptographically secure random source. The probability of two random v4 UUIDs colliding is about 1 in 2^122 — you could generate a billion per second for decades without a realistic chance of a duplicate. They are, however, identifiers, not secrets: don't use a UUID as a password or session token by itself.
What is the difference between a UUID and a GUID?
Nothing meaningful — GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit standard, historically written in uppercase and sometimes wrapped in braces. If a Windows or .NET system asks for a GUID, generate a UUID here and tick the uppercase option if the target is case-sensitive about it.
Can I generate UUIDs in bulk for database seeding?
Yes — set the count up to 1,000 and copy the whole list; each UUID sits on its own line, ready to paste into a CSV, SQL script or test fixture. Need more than 1,000? Generate several batches; uniqueness is unaffected because every UUID is independent.
Is it safe to use these UUIDs in production?
Yes. Generation happens entirely in your browser with the standard Web Crypto API — the identifiers are never sent to or stored on a server, so no one else ever sees them. They are exactly as random as UUIDs generated by your own backend code.