UUID v4 Generator
Free UUID v4 generator — create one or hundreds of cryptographically strong UUIDs in your browser and copy them with one click.
About UUID v4
A version-4 UUID packs 122 random bits into the familiarxxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx shape — the collision probability is so small you can treat them as globally unique. This tool uses your browser's crypto.randomUUID(), which draws from the operating system's CSPRNG. Nothing is generated on a server.
Frequently asked questions
What is a UUID v4?
A 128-bit identifier with 122 random bits, written as xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. The “4” marks the version; the randomness comes from a cryptographically secure generator.
Can two UUIDs collide?
In theory yes, in practice no — you would need to generate about 2.7×10¹⁸ UUIDs for a 50% chance of a single collision. Treat them as unique.
Are these UUIDs generated securely?
Yes — this tool calls your browser's crypto.randomUUID(), which uses the operating system's CSPRNG. Generation happens locally; the IDs are never sent anywhere.
Can I generate UUIDs in bulk?
Yes — set the count (up to 500 at a time), and copy the whole list with one click. Options let you uppercase them or strip dashes.