UUID Generator
Generate random v4 or time-ordered v7 UUIDs in bulk, in whichever format you need. Produced locally using your browser's cryptographic random source.
122 bits of randomness. The default choice when you just need a unique value.
Generating…
What the UUID Generator does
- Generates random v4 UUIDs and time-ordered v7 UUIDs in your browser.
- Produces up to 100 at once, using the platform's cryptographic random source.
- Offers uppercase, dash-free, braced and URN formats alongside the standard form.
- Explains what each version is for, so you can pick deliberately.
What it doesn't do
- It doesn't generate v1, v3 or v5 UUIDs.
- It doesn't check whether a UUID already exists in your system.
- It doesn't validate or parse UUIDs you already have.
Frequently asked questions
Should I use v4 or v7?
Use v7 for database primary keys. Its leading timestamp means new rows sort to the end of the index instead of scattering across it, which keeps inserts fast and improves locality. Use v4 anywhere the value is just an identifier and revealing creation time would be undesirable.
Can two UUIDs ever collide?
In theory yes, in practice no. A v4 UUID carries 122 random bits; you would need to generate billions per second for decades before a collision became likely. Every value here comes from a cryptographic random source, not a predictable one.
Does a v7 UUID leak information?
It encodes the creation time to the millisecond, which is deliberate. If exposing when a record was created matters — publicly numbered resources, for instance — use v4 instead.