UUID Generator

Generate random UUIDs (v4) instantly in your browser. Perfect for database IDs, unique identifiers, and testing.

Click "Generate" to create UUIDs

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UUID Generator

Generate UUID v4 identifiers instantly. Bulk generation supported for database seeding and testing.

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Check npm package bundle sizes and analyze dependencies before adding them to your project.

What is a UUID?

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit number used to uniquely identify information in computer systems. UUIDs are standardized by the Open Software Foundation (OSF) as part of the Distributed Computing Environment (DCE).

Our UUID generator creates Version 4 UUIDs using the browser's built-in crypto.randomUUID() function, which generates cryptographically strong random values. The format is: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

Why Use UUIDs?

  • Global Uniqueness: No central coordination needed - generate IDs anywhere
  • Collision-Resistant: Virtually impossible to generate duplicates (1 in 2¹²² chance)
  • Privacy-Friendly: Don't reveal creation time or device info (unlike v1 UUIDs)
  • Database-Friendly: Perfect for distributed systems and primary keys
  • Non-Sequential: Can't be guessed or enumerated like auto-increment IDs

Common Use Cases

Database Primary Keys

Use as unique identifiers in databases, especially in distributed systems where auto-increment IDs don't work well.

API Resources

Generate unique IDs for API resources, preventing enumeration attacks and hiding the number of records.

Session IDs

Create secure, unpredictable session identifiers for authentication systems.

File Names

Generate unique file names for uploads to prevent collisions and overwriting.

Testing & Mocking

Create realistic test data with unique identifiers for unit tests and mock APIs.

Message Queues

Track messages across distributed systems with guaranteed unique identifiers.

UUID Format Explained

550e8400-e29b-41d4-a716-446655440000

550e8400
Time Low
(8 hex digits)
e29b
Time Mid
(4 hex digits)
41d4
Version + Time Hi
(4 hex digits)
a716
Variant + Clock
(4 hex digits)
446655440000
Node
(12 hex digits)

Version 4 UUIDs use random data for all sections except the version (4) and variant bits.

How It Works

  1. Select how many UUIDs you need (1-100)
  2. Optionally choose uppercase format
  3. Click "Generate" to create UUIDs using crypto.randomUUID()
  4. Click any UUID to copy it individually, or use "Copy All" for bulk copying

Privacy Note: All UUIDs are generated entirely in your browser using the Web Crypto API. No server calls, no tracking, completely private.

UUID vs GUID: What's the Difference?

There is no practical difference. "UUID" is the standard term used in most contexts, while "GUID" is Microsoft's term for the same concept. They both refer to the same 128-bit unique identifiers and are fully interchangeable.