Mock user IDs
Sample settings
Quantity: 3
Sample output
- 0f5fad5b-d9cb-469f-a165-70867728950e
- 7c9e6679-7425-40de-944b-e07fc1f90ae7
- f47ac10b-58cc-4372-a567-0e02b2c3d479
UUID Generator
Generate RFC 4122 version 4 UUIDs for development, testing, and sample data.
Generatorsavailable
Choose a quantity, then generate UUIDs.
Generated UUIDs will appear here.
About UUID Generator
Use the UUID Generator to create one or more version 4 UUIDs for development, testing, mock data, documentation, temporary records, and database examples. Choose a quantity, generate browser-based UUIDs, then copy individual values, copy the full list, or download the results as a text file.
How to use
- Enter how many UUIDs you want to create.
- Click Generate to create the UUID list.
- Copy a single UUID when you only need one value.
- Use Copy All when you want the full list on your clipboard.
- Download the list as a text file if you need to save or share the generated values.
Worked example
Features
- Generates RFC 4122 version 4 UUIDs.
- Supports quantities from 1 to 100 UUIDs at a time.
- Uses browser-native secure randomness where available.
- Lets you copy one UUID or the full generated list.
- Downloads generated UUIDs as a plain text file.
- Runs in the browser without requiring an account.
How it works
- The quantity is normalized to a whole number between 1 and 100 before generation.
- The generator uses the browser's native crypto.randomUUID method when it is available.
- If crypto.randomUUID is not available, it falls back to crypto.getRandomValues and sets the version and variant bits for UUID v4 format.
- Each generated value is checked against an RFC 4122 version 4 pattern before it is shown.
- Generated UUIDs are displayed in a list so each value can be copied individually.
- The download action creates a local text file from the current generated list.
Common use cases
- Creating IDs for seed data, fixtures, and mock records.
- Testing forms, APIs, queues, and database workflows.
- Preparing sample identifiers for documentation and support examples.
- Adding placeholder IDs to prototypes, demos, and design handoff notes.
- Generating temporary correlation IDs while debugging local workflows.
- Creating realistic-looking record identifiers for screenshots and test plans.
Frequently asked questions
What is a UUID used for?
A UUID is commonly used as a unique identifier in software, databases, test data, and integrations.
What type of UUID does this tool generate?
The tool generates UUID version 4 values, which are random UUIDs commonly used in development and testing workflows.
How many UUIDs can I generate at once?
You can generate between 1 and 100 UUIDs at a time. Values outside that range are normalized before generation.
Does the UUID Generator use secure randomness?
Yes. It uses browser-native cryptographic randomness through crypto.randomUUID or crypto.getRandomValues where available.
Can I copy one UUID at a time?
Yes. Each generated UUID has its own copy button, and you can also copy the entire list at once.
Can I download generated UUIDs?
Yes. Use Download to save the current generated UUID list as a plain text file.
Are generated UUIDs stored by ToolMetro?
No. UUIDs are generated in your browser and are not stored by ToolMetro.
Are UUIDs guaranteed to be unique?
UUID v4 values are designed to have an extremely low chance of collision, but no random identifier system can honestly promise absolute uniqueness in every possible context.
Can I use these UUIDs in a database?
Yes. UUID v4 values are commonly used for database records, test rows, fixture data, and temporary records. Follow your database schema and application requirements.
Is a UUID the same as a GUID?
The terms are often used interchangeably in everyday development. GUID is common in Microsoft contexts, while UUID is the standard name used more broadly.