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Click "Generate UUID" to create your first UUID v4

How to Use

  1. 1
    Click Generate

    Press the "Generate UUID" button to instantly create a new UUID v4 using your browser's secure crypto API.

  2. 2
    Copy the UUID

    Click the Copy button next to any UUID to copy it to your clipboard in one click.

  3. 3
    Generate multiple

    Click Generate multiple times to build a history of up to 10 UUIDs. Use "Copy All" to grab all of them at once.

  4. 4
    Use in your project

    Paste the UUID into your database, config file, or code wherever a unique identifier is needed.

Common Use Cases

database

Database Primary Keys

Use UUID v4 as primary keys in SQL or NoSQL databases to ensure globally unique identifiers without coordination between services.

lock

Session Tokens

Generate secure, random session tokens or CSRF tokens for your web applications with zero collision risk.

folder

File Naming

Rename uploaded files with UUIDs to avoid name collisions and prevent users from guessing file paths on your server.

api

API Resources

Identify REST API resources, webhook delivery IDs, or idempotency keys with universally unique identifiers safe to expose in URLs.

Frequently Asked Questions

What is UUID v4?

UUID v4 (Universally Unique Identifier version 4) is a 128-bit identifier generated using random or pseudo-random numbers. It follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx and has an astronomically low collision probability.

How is the UUID generated?

This tool uses the browser's built-in crypto.randomUUID() method, which is part of the Web Crypto API. It produces cryptographically strong random UUIDs directly in your browser — no server involved.

Is my data sent to a server?

No. UUID generation happens entirely in your browser using the Web Crypto API. Nothing is transmitted to any server.

Can two UUIDs ever be the same?

In theory yes, but the probability is negligible. With UUID v4 there are 2^122 possible values (~5.3 × 10^36). The chance of a collision across billions of generated UUIDs is effectively zero.

What is the format of a UUID v4?

A UUID looks like: 550e8400-e29b-41d4-a716-446655440000. It consists of 32 hexadecimal digits split into five groups separated by hyphens (8-4-4-4-12). The first digit of the third group is always "4" and the first digit of the fourth group is "8", "9", "a", or "b".

Can I generate multiple UUIDs at once?

Yes. Click "Generate UUID" multiple times to build a history of up to 10 UUIDs. You can then use "Copy All" to copy all of them to your clipboard at once, separated by newlines.