UUID Generator

UUID v4 is the most common version of UUIDs. It's based on random numbers, which are generated using a cryptographically secure random number generator. This ensures that the UUIDs are unique and secure. You can create a UUID v4 by using our online UUID generator tool. Simply click the "Randomize" button, and a new UUID v4 will be created for you. You can then copy the UUID and use it in your projects.

A UUID (Universally Unique Identifier) is a 128-bit identifier that helps keep your data organized and conflict-free. Whether you're building a small application or managing enterprise systems, UUIDs provide a reliable way to identify information without worrying about duplicates. Version 4 UUIDs have become the industry standard because they offer the perfect balance of simplicity and security through random generation - much like our random number generator but designed specifically for unique identification.

We've kept things straightforward. This tool generates UUIDs that follow RFC 9562 using your browser's cryptographically secure random number generator. Simply click "Randomize" to generate a new UUID, then copy it with a single click. Each identifier is genuinely unique and production-ready, whether you need one for testing or a critical system. If you're working with different encoding formats, you might also find our Base64 encoder useful for data transformation. To put a UUID on a physical label or asset for scanning, encode it in a QR code.

UUIDs solve real problems across various scenarios:

• Database Management - Replace sequential IDs with UUIDs to avoid conflicts when merging databases or scaling systems
• Distributed Architecture - Generate unique identifiers across multiple services without needing a central authority
• Development and Testing - Create test data with identifiers that are unique in practice, alongside other testing tools such as the JSON formatter
• Session Management - Implement secure session tracking in web applications alongside strong passwords for complete security
• Document and File Systems - Ensure unique naming conventions for uploads and storage, similar to how MD5 hashes create unique file fingerprints
• Audit and Logging - Track specific events and transactions throughout complex workflows

Each UUID follows the standard format: 1a4ad0a4-cd0f-4ead-861d-1994eacd154d - that's 32 hexadecimal characters arranged in five groups. When working with different data formats, you might need our hex to text converter for debugging purposes.

Version 4 UUIDs draw on 122 bits of randomness, which makes a collision vanishingly unlikely in practice rather than impossible. RFC 9562 (which replaced RFC 4122) defines a single text format, so the same UUID is read consistently across platforms, programming languages, and databases. For URL-safe implementations, consider our URL encoder to properly format UUIDs in web addresses.

Very secure. They use cryptographically strong random number generation, making them impossible to predict or reverse-engineer. For other security needs, explore our password generator which uses similar cryptographic principles.

Practically zero. You'd need to generate about 1 billion UUIDs per second for 85 years to have a 50% chance of one collision. In real-world applications, duplicates simply don't happen.

It's not necessary. The mathematical probability is so low that major systems worldwide rely on UUIDs without collision checking. We've never encountered a genuine collision in production environments.

No, and they shouldn't. UUIDs are identifiers, not encryption tools. They're designed to be unique and public-facing, perfect for referencing data but not for protecting it. For encoding needs, use our UTF-8 encoder or Base64 tools instead.

Absolutely. The UUIDs generated here meet the same standards used in enterprise applications, cloud services, and critical infrastructure systems. When formatting them for different uses, our JSON stringify tool can help prepare them for API payloads.

This tool generates v4 and v7 UUIDs. Here is how the main versions differ:

If you need v1, v3, v5, or ULID generation, libraries like uuid (npm) or python-ulid handle those formats.

A version 7 UUID begins with a 48-bit Unix timestamp in milliseconds, followed by the version number, 12 bits that keep IDs made in the same millisecond in order, and 62 random bits. Because the time comes first, v7 UUIDs sort in the order they were created, which keeps database indexes compact and makes logs easy to scan. The trade-off is that anyone holding a v7 UUID can read when it was made, so use v4 where the creation time should stay private.

They change how the UUID is written, not its value. RFC 9562 uses lowercase with hyphens, which is the default here. Some systems, such as older Microsoft tools, show GUIDs in uppercase and wrapped in braces, like {1A4AD0A4-CD0F-4EAD-861D-1994EACD154D}, and some databases store the 32 digits without hyphens. Parsers generally accept any of these forms, but keep to one format within a system so that string comparisons match.