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Guide · Developer tools

How to generate random UUIDs (v4)

Fixtures, seed data, correlation IDs, a primary key you need right now — a UUID v4 is one click away. Set the quantity, pick the display format, and copy values produced by your browser's own cryptographic generator.

Open the free uuid generator →Free · no signup · no watermarks

Step by step

01

Open the UUID generator

Start the free generator — it runs entirely in your browser.

02

Choose how many you need

Any quantity from 1 to 100 per run; each value gets its own call to crypto.randomUUID().

03

Pick the display format

Lowercase or uppercase, with or without hyphens — the canonical hyphenated lowercase form is what most databases expect.

04

Generate

Each value is a version 4 UUID: the 4 in the third group marks the version, and the leading bits of the next group encode the RFC variant.

05

Copy or download

Move the values into your fixture, seed script, or SQL insert.

Tips that save a second try

↳
Tip 01

The case and hyphen toggles only change how the same generated bytes are displayed — they do not request fresh randomness.

↳
Tip 02

Keep the canonical hyphenated form unless you know the target system accepts otherwise; removing hyphens can conflict with systems that require canonical text.

↳
Tip 03

A UUID is an identifier, not a secret — never use one as an API key, token, or password.

Common questions

Do the uppercase and no-hyphen options generate new values?

No. Those controls only change how the same generated bytes are displayed — toggling them does not request fresh randomness.

Can a generated UUID be used as an API key?

It should not be treated as one. Uniqueness and random generation do not provide key lifecycle, secrecy, permissions, or revocation.

Ready to do it? UUID generator → · More developer tools · All guides

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