UUID Generator
Generate random UUID v4 identifiers instantly. Bulk generate, format, and copy UUIDs with one click.
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Generate UUIDs
Generated UUIDs
Click "Generate UUID" to create your first UUID
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How to Use the UUID Generator
This UUID generator creates cryptographically secure random UUID v4 identifiers instantly. Click the "Generate" button to create a new UUID, or use the bulk generation feature to create multiple UUIDs at once.
Each generated UUID follows the standard v4 format (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx), where the '4' indicates version 4 and 'y' is one of 8, 9, A, or B. The remaining characters are cryptographically random hexadecimal digits.
Formatting options let you choose between standard hyphenated format, uppercase, no hyphens, or braces (Microsoft GUID style). The one-click copy button makes it easy to paste UUIDs into your code, database, or configuration files.
UUIDs are essential in modern software development for creating unique identifiers without a centralized ID server. They're used extensively in distributed databases, microservices architectures, RESTful APIs, and anywhere unique identification is needed across systems.
Frequently Asked Questions
What is a UUID?
UUID stands for Universally Unique Identifier. It's a 128-bit number used to uniquely identify information in computer systems. UUIDs are formatted as 32 hexadecimal digits displayed in five groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. They're designed to be unique across space and time without a central authority.
What is the difference between UUID and GUID?
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are essentially the same thing. GUID is the term used by Microsoft, while UUID is the industry standard term defined in RFC 4122. Both refer to a 128-bit identifier with the same format and generation methods.
How unique is a UUID v4?
UUID v4 uses random number generation to produce identifiers with 122 bits of randomness. The probability of generating a duplicate is astronomically low — you would need to generate about 2.71 quintillion UUIDs to have a 50% chance of a collision. For all practical purposes, UUID v4 values are unique.
When should I use UUIDs?
UUIDs are ideal for: database primary keys (especially in distributed systems), API resource identifiers, session tokens, correlation IDs for logging, file names for uploaded content, and any situation where you need a unique identifier without checking a central database.
Are UUIDs generated here truly random?
Yes. This tool uses the browser's crypto.randomUUID() API (or crypto.getRandomValues() as fallback), which provides cryptographically secure random number generation. The UUIDs are generated entirely in your browser and are never sent to any server.