GUID Generator

One GUID, or thousands, made in your own browser.

FREE - NO SIGN-UP - RUNS ON YOUR DEVICE

Runs in your browser tab

  • 1or thousands
  • v4RFC 4122
  • 0uploads
  • 1 tapto copy
Specification

GUID Generator at a glance

Input
A count
Output
v4 identifiers, ready to copy
GUID or UUID
Two names, one identifier
Method
crypto.randomUUID, in the browser
Version
Version 4 only
Price
Free
Account needed
None
Where processing happens
On your device
How to

How to use GUID Generator

  1. 1

    Say how many

    Enter how many you need.

  2. 2

    Take the list

    Read the generated list.

  3. 3

    Take the whole set

    Copy the set, or save it as a file.

Questions

Frequently asked questions

Is a GUID the same as a UUID?

Yes. They are two names for the same 128-bit identifier, written the same way. Anything that expects a UUID accepts what is generated here.

Could two of these ever collide?

Version 4 draws its bits from the browser's cryptographic random source, which is what makes a repeat not worth planning for. No generator can promise a value has never appeared elsewhere.

Which version are these?

Version 4, the random one. Time-ordered versions that sort by creation are not produced here, so use another source if your database needs sequential keys.

Are the values generated on a server?

No. crypto.randomUUID runs in this browser tab. The values never leave the device, are not logged, and are not stored anywhere.

Background

Where a v4 identifier fits

Say how many you need and they appear together. GUID and UUID are two names for the same 128-bit value, and these are the RFC 4122 version 4 form.

  • A random identifier can be made before a row exists, which is why it suits offline clients and split systems.
  • Version 4 values do not sort by creation time, so an index on one scatters writes across the table.
  • Ask for a batch when seeding fixtures, rather than generating them one at a time.
  • Nothing about the value encodes a machine, a time or an account; the bits are random and carry no meaning.

Full specification

Specification of the GUID Generator tool
InputHow many identifiers you want in one go.
OutputOne or many RFC 4122 version 4 values, listed together for copying.
GUID or UUIDThe same 128-bit identifier under two names. Anything expecting a UUID takes these.
Methodcrypto.randomUUID, the browser's own cryptographic random source.
VersionVersion 4, which is random. Time-ordered and sequential versions are not produced here.
PriceFree. Supported by clearly labelled ads outside the working area.
Account neededNo.
Where processing happensIn your browser tab. Your input is never uploaded.
Next step

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