UUID Generator
Generate random version-4 UUIDs (GUIDs) — one or thousands at a time, with optional uppercase, no-hyphen and braces formatting. Everything runs in your browser using a cryptographic random source, and nothing is uploaded.
UUIDs are generated on your device — nothing is sent anywhere.
How to use the UUID generator
By default you get a single random version-4 UUID the moment the page loads. Press Generate for a fresh one, or set How many and generate up to 1,000 at once — handy for seeding a database, mocking test data, or filling a column of identifiers. Press Copy to put the whole list on your clipboard.
Use the formatting options to match your target system: Uppercase switches the hex digits to A–F, Remove hyphens gives the compact 32-character form, and Wrap in braces produces the {…} style Microsoft tools often expect. Need a placeholder? Nil UUID inserts the all-zero identifier.
Every value comes from your browser's cryptographic random source — the UUIDs never leave your device.
Common questions
UUID or GUID — what's the difference? None, in practice. GUID is Microsoft's name for the same 128-bit identifier. This tool produces standard RFC 4122 values that are valid as either.
Could two generated UUIDs ever collide? A version-4 UUID has 122 random bits. The odds of a collision are so small that they are ignored in practice — you would need to generate billions of UUIDs before a clash became remotely likely.
Can I generate version-1 (time-based) UUIDs? This tool generates version 4 (random), which is the right choice for almost every use case and avoids leaking a MAC address or timestamp. Version 1 is intentionally not offered.
Is anything saved or uploaded? No. The tool is fully client-side — your UUIDs never leave your browser and nothing is stored.