Free UUID Generator - Generate Random UUIDs Online

Generate random UUIDs (Universally Unique Identifiers) online for free. Create unique identifiers for databases, APIs, and applications. Our generator produces version 4 UUIDs with cryptographic randomness—the standard for unique identification across systems.

What Is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across space and time. UUIDs are used when you need unique identifiers without central coordination—unlike sequential IDs that require a central authority.

Standard UUID format:

xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx

Example: 550e8400-e29b-41d4-a716-446655440000

How to Use

1. Click "Generate" - Create a new UUID instantly
2. Generate multiple - Create bulk UUIDs if needed
3. Choose format - Standard, uppercase, no hyphens, etc.
4. Copy result - Use in your application
5. Generate more - No limits on generation

Key Features

• Version 4 UUIDs - Random generation (most common)
• Cryptographic randomness - True unpredictability
• Bulk generation - Create multiple UUIDs at once
• Multiple formats - With/without hyphens, case options
• One-click copy - Easy clipboard access
• No storage - UUIDs are never saved

UUID Versions Explained

Version 4 (Our Generator)

Version 4 UUIDs are generated using random numbers. The only fixed bits are:

• Version bits (4 bits set to '0100' = 4)
• Variant bits (2 bits set to '10')

This leaves 122 random bits, providing approximately 5.3 × 10^36 possible UUIDs.

UUID Format Variations

Use Cases

Databases

• Primary keys - Unique record identifiers
• Distributed systems - IDs across multiple databases
• Data merging - Non-colliding identifiers
• Anonymization - Replace sequential IDs

APIs & Web Development

• Request IDs - Track API calls
• Session tokens - User session identification
• Correlation IDs - Trace requests across services
• Resource identifiers - RESTful API resources

Software Development

• Object identifiers - Unique instance IDs
• File naming - Unique temporary files
• Transaction IDs - Financial/order tracking
• Event sourcing - Event identification

DevOps & Infrastructure

• Container IDs - Docker/Kubernetes
• Deployment IDs - Track releases
• Instance IDs - Cloud resources
• Log correlation - Link related log entries

UUID Collision Probability

With 122 random bits, the probability of generating duplicate UUIDs is astronomically low:

For practical purposes, UUID collisions are impossible in any real-world application.

UUID vs. Other Identifiers

UUID in Code

JavaScript

crypto.randomUUID(); // Modern browsers

Python

import uuid
str(uuid.uuid4())

Java

UUID.randomUUID().toString();

PHP

wp_generate_uuid4(); // WordPress
Str::uuid(); // Laravel

Frequently Asked Questions

Are UUIDs truly unique?

For all practical purposes, yes. The probability of collision is so low (roughly 1 in 2^122) that it's effectively impossible in any real-world scenario.

Can I use UUIDs as passwords?

No. While UUIDs are random, they follow a predictable format and length. Use dedicated password generators for security purposes.

Why use UUIDs instead of auto-increment IDs?

• No central authority needed - Generate anywhere
• Distributed systems - No coordination required
• Privacy - Don't reveal record counts
• Data merging - No ID conflicts

Are UUIDs sequential or sortable?

Version 4 UUIDs are random and not sortable by creation time. If you need sortable IDs, consider ULIDs or UUID v7.

Can someone guess a UUID?

Guessing a specific UUID is practically impossible with 122 random bits. However, don't rely on UUIDs for security—they're identifiers, not secrets.

What's the difference between UUID and GUID?

GUID (Globally Unique Identifier) is Microsoft's term for the same concept. They're functionally identical.