UUID Generator
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About this tool
A UUID (Universally Unique Identifier) is a 128-bit value used to label something uniquely without a central authority handing out numbers. This generator produces version 4 UUIDs, which are almost entirely random, and version 7 UUIDs, which begin with a timestamp so they sort in the order they were created — handy as database keys.
The random bits come from the Web Crypto API, so the values are suitable for real use, not just demos. You can generate a batch at once, output them in uppercase, and strip the dashes if your system prefers a compact form.
Generation is entirely local to your browser.
How to use
- Choose the version: v4 for pure random, v7 for time-sortable.
- Set how many you need and any format options such as uppercase or no dashes.
- Press Generate.
- Copy a single value, or Copy All to grab the whole batch.
Common use cases
- Primary keys for database rows that must not collide across systems
- Correlation and request IDs in distributed systems and logs
- Idempotency keys for API calls
- Unique file or resource names
Frequently asked questions
Which UUID version should I use?
v4 (random) is the most common choice for unique IDs. Use v1 only when you need time-ordered identifiers.
Are these UUIDs guaranteed to be unique?
v4 UUIDs have 122 random bits, making collisions astronomically unlikely for practical purposes.
Can I generate many at once?
Yes, set the count and copy them all together — generation runs entirely in your browser.
What is the advantage of v7 over v4?
v7 embeds a timestamp at the start, so identifiers sort roughly by creation time. This keeps database indexes efficient, unlike fully random v4 keys which scatter writes.
Is a UUID a security secret?
No. A UUID is unique but not unguessable in the cryptographic sense, and v7 even reveals creation time. Do not use one on its own as a password or session secret.