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UUID v4 Generator

Generate UUID v4 identifiers using your browser’s cryptographic random API when supported. Create one identifier or a batch for development tasks.

Tool workspace

Privacy note: this tool runs in your browser. Do not use any online service for secrets unless its privacy and security practices meet your needs.

About this tool

About UUID v4 Generator

The UUID v4 Generator creates random universally unique identifiers in the standard 36-character format. You can generate a single ID or several at once and copy them straight into your database, code or test data.

UUIDs are used as record identifiers, file names, session tokens and correlation IDs because the chance of two random version 4 values colliding is extremely small. They are identifiers, not secrets, so do not use them as passwords.

A UUID is an identifier that is extremely unlikely to repeat, even when many systems create them independently. Version 4 UUIDs are generated from random numbers, which makes them a convenient choice for database keys, file names and request identifiers.

The tool creates one or many UUIDs at once and lets you copy them directly. Because they are random, they reveal nothing about when or where they were created.

Step by step

How to Use UUID v4 Generator

  1. 1
    Choose how manySelect the number of UUIDs you need.
  2. 2
    GeneratePress the generate button to create random version 4 identifiers.
  3. 3
    Review the valuesEach UUID follows the standard pattern of five groups separated by hyphens.
  4. 4
    Copy and useCopy the list into your code, spreadsheet or database.
Real-world use

Where UUID v4 Generator helps most

Database keysCreate unique identifiers without a central counter.
File and upload namesAvoid name collisions when many files are saved.
Test dataGenerate batches of identifiers for tests and examples.
Request tracingTag requests across services so you can follow them in logs.
Get better results

Practical tips for UUID v4 Generator

  • Generate in bulk when you need many values, and copy them in one step.
  • Store UUIDs in a native UUID or fixed-length column where your database supports it.
  • Do not use UUIDs as secrets or access tokens.
  • Keep the lowercase hyphenated form for consistency.
  • Validate the format before accepting UUIDs from users.

Common mistakes to avoid

  • Using a UUID as a password or secret link.
  • Assuming UUIDs sort in creation order.
  • Editing a UUID by hand, which can make it invalid.
Benefits

Why Use UUID v4 Generator

Standard formatGenerates valid version 4 UUIDs that work in common languages and databases.
Bulk generationCreate many identifiers at once for tests and seed data.
Browser-basedGeneration happens locally without any server request.
Easy copyCopy a single value or the whole list quickly.

Good to know. This tool runs in your browser, so the text you enter is processed on your own device. Even so, avoid pasting real passwords or secrets into any online tool. See the Privacy Policy for details.

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Questions & answers

Frequently Asked Questions

What is a UUID?
A UUID is a 128-bit identifier written as 32 hexadecimal characters in five hyphen-separated groups, designed to be unique without a central authority.
What does version 4 mean?
Version 4 UUIDs are generated from random numbers, unlike other versions that use timestamps or names.
Can two UUIDs ever be the same?
In theory yes, but the probability for random version 4 values is so small that it is ignored in practice.
Are UUIDs secure tokens?
No. They are meant to be unique identifiers. Use a dedicated secret generator for passwords and security tokens.
Where are UUIDs used?
Common uses include database primary keys, file names, API request IDs and distributed system identifiers.
Are generated values stored?
No. They are created in your browser and not stored or transmitted by this page.