UUID Generator
Generate random UUID v4 identifiers in your browser, one or several at a time, and copy them. Nothing is uploaded.
A free UUID generator that creates random version 4 identifiers, right in your browser. UUIDs (universally unique identifiers) are 128-bit values written as 36-character strings, used as keys and IDs that are practically guaranteed not to collide. Choose how many you want, generate, and copy any one or all of them. The randomness comes from the browser’s crypto API, and nothing is uploaded or stored. Refresh or click generate for a fresh set.
How to use this tool
- 01Choose how manyPick 1, 5, or 10 UUIDs to generate at once.
- 02GenerateThe UUIDs appear immediately; click generate again for a new set.
- 03CopyCopy a single UUID, or copy them all as a list.
When is this useful?
- Database keysCreate unique primary keys or record IDs for development and testing.
- Idempotency keysGenerate a unique key for an API request or a transaction.
- Test dataProduce a batch of unique identifiers for seeding or fixtures.
Examples
- A single UUIDOne click gives a value like the standard 8-4-4-4-12 hexadecimal pattern.
- A batch of tenChoose 10 to get a list you can paste straight into a seed file.
- Version 4Every value is a version 4 (random) UUID, with the version and variant bits set correctly.
Formula or how the tool works
The tool uses the browser’s crypto.randomUUID when available, or a fallback that fills 16 random bytes from crypto.getRandomValues and sets the version 4 and variant bits before formatting them as the 8-4-4-4-12 hex string.
Inputs, outputs, and assumptions
You choose a count. The tool returns that many version 4 UUIDs. It assumes the browser provides a secure random source, which all modern browsers do.
Supported modes or scenarios
Generate one for a quick key or a batch for seeding. Regenerate as often as you like; each set is independent.
Limitations and common mistakes
These are version 4 (random) UUIDs, not time-ordered version 1 or 7 UUIDs, so they do not sort by creation time. UUIDs are unique enough for keys but are not secrets; do not use one as a password or token on its own.
Privacy and local processing
UUIDs are generated in your browser using its crypto API. Nothing is uploaded or stored, and generation happens on the client so values never touch a server.
Frequently asked questions
What version of UUID is this?
Version 4, which is random. The version and variant bits are set according to the standard.
Are the UUIDs really unique?
Version 4 UUIDs have 122 random bits, so collisions are astronomically unlikely for normal use.
Can I use a UUID as a password?
No. UUIDs are identifiers, not secrets. Use a password generator for credentials.
Do they sort by time?
No. Version 4 UUIDs are random, so they do not order by creation time. Use version 7 elsewhere if you need that.
Is anything uploaded?
No. Generation happens in your browser and nothing is sent to a server.
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