UUID Generator

Generate UUID and ULID values for identifiers, APIs, and distributed systems. Free online developer tool for fast browser-based work.

What is this tool?

UUID Generator creates unique-looking identifiers for test records, logs, mocks and sample payloads. It helps teams avoid reusing IDs copied from production systems.

How to use

Choose how many identifiers you need for the current test or fixture.
Generate UUIDs or ULIDs depending on whether your system needs random or sortable identifiers.
Copy the result into mock data, API examples, database seeds or test assertions.

Type

Quantity

Generated locally in your browser.

Result

Use the button to create test identifiers.

Practical example

A generated UUID is useful as a request ID in a reproducible API example.

{
  "requestId": "generated-uuid",
  "status": "draft",
  "source": "qa-fixture"
}

API

Use the UUID API endpoint for repeatable automation that needs fresh IDs without depending on a database.

View API Docs

When to use

LOG

Correlation IDs

Attach IDs to test requests and logs during troubleshooting.

Seed records

Fill non-production records with stable-looking identifiers.

API

Mock payloads

Create request IDs for examples, demos and integration notes.

Automation

Generate many identifiers without manual copy/paste.

Privacy

Generated identifiers are test values. Do not mix them with real customer IDs when creating public examples or support notes.

Frequently asked questions

Are generated UUIDs guaranteed to be unique?

UUIDs are designed to make collisions extremely unlikely, but applications should still enforce uniqueness where required.

When should I use ULID instead of UUID?

Use ULID when sortable identifiers are helpful for logs, fixtures or time-ordered records.

Can I use generated IDs in production?

Use your application identity strategy in production. This tool is best for tests, demos and non-production fixtures.

Limitations / when not to use

A generated UUID does not confirm that an object exists in your system. It is only an identifier string until your application stores or references it.