UUID v4 Generator
Get random version 4 UUIDs, the everyday choice for unique IDs when you do not need ordering or repeatability.
Processed locally in your browser/ Your data stays in your browser.
What is UUID v4 Generator?
A version 4 UUID is made almost entirely of random bits: 122 of its 128 bits come from a random source, and the remaining six mark the version (4) and the variant. There is no timestamp, no MAC address and no hidden structure, so the value reveals nothing about when or where it was created.
This page is tuned for that one job. It produces ten UUIDs by default, and you can change the count, switch to uppercase, remove hyphens, wrap each value in braces or quotes, and copy the list as text, CSV or a JSON array.
How does it work?
- Choose a quantity; ten is preselected, and up to 1,000 are allowed.
- Toggle uppercase, hyphens and wrapper to match your target format (for example {…} for GUIDs in .NET).
- Press Generate to create a fresh batch; every press gives all-new values.
- Copy the result or download it as a text, CSV or JSON file.
Common use cases
- Session, request and idempotency keys in web services.
- Placeholder IDs in fixtures, mock APIs and unit tests.
- Filenames or object-storage keys that must not clash.
- Client-generated primary keys when order does not matter.
Examples
Get random version 4 UUIDs, the everyday choice for unique IDs when you do not need ordering or repeatability.
Privacy
UUID v4 Generator runs entirely in your browser. The text or files you provide are processed on your device and are not uploaded, logged or stored on our servers.
Limitations
A v4 UUID is unpredictable enough for identifiers, but do not treat it as a secret token. Because v4 values are random, they scatter across a database index; use UUID v7 if index locality matters.
Frequently asked questions
How random is a UUID v4?
It carries 122 random bits taken from the browser’s cryptographically secure generator, which is far more than needed to avoid collisions in any practical system.
What is the difference between UUID and GUID?
GUID is Microsoft’s name for the same 128-bit format. A v4 GUID and a v4 UUID follow the same layout; GUIDs are often written in braces and sometimes in uppercase, which you can reproduce with the options here.
Why not use UUID v7 for everything?
v7 leaks the creation time in its first 48 bits. If you do not want that, or you prefer pure randomness, v4 is the better fit.
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