UUID Generator
RFC4122 Compliant
Generate universally unique identifiers instantly. Supports UUID v1 (timestamp), v3 (MD5), v4 (random), and v5 (SHA-1). Perfect for database keys, API resources, distributed systems, and microservices. 100% client-side - your UUIDs never leave your browser.
UUID Configuration
UUID Inspector
Paste a UUID to validate and inspect its properties
UUID Quick Reference
UUID v4 - Random
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
122 bits of cryptographically secure randomness. Most widely used UUID version.
UUID v1 - Timestamp
xxxxxxxx-xxxx-1xxx-yxxx-xxxxxxxxxxxx
Time-based with 100-nanosecond precision. Sortable by creation time.
UUID v5 - SHA-1
xxxxxxxx-xxxx-5xxx-yxxx-xxxxxxxxxxxx
Deterministic hash-based. Same input always produces same UUID.
UUID v3 - MD5
xxxxxxxx-xxxx-3xxx-yxxx-xxxxxxxxxxxx
Legacy MD5 hash-based. Use v5 instead for better security.
Common Use Cases
Use v4 for unique, unpredictable record identifiers
Use v4 for REST API resources and endpoints
Use v1 for time-ordered event IDs in logs
Use v5 for deterministic content-based IDs
Why We Built This UUID Generator
Universally Unique Identifiers (UUIDs) are the backbone of modern distributed systems, microservices architectures, and database design. However, developers often struggle with choosing the right UUID version for their use case, understanding the trade-offs between different versions, and accessing a reliable tool that supports all RFC4122 UUID versions. Many online UUID generators only support UUID v4, leaving developers without options when they need timestamp-based v1 UUIDs for time-ordered records, deterministic v5 UUIDs for content-addressed storage, or v3 UUIDs for legacy system compatibility. This comprehensive UUID generator tool was created to provide developers with a complete UUID generation solution that supports all four UUID versions, includes format customization, batch generation, and UUID inspection capabilities - all while maintaining complete privacy by generating UUIDs entirely client-side in your browser.
Our UUID validator and generator fills a critical gap in the developer tooling ecosystem. Whether you are building REST APIs that need unique resource identifiers, designing database schemas with UUID primary keys, implementing event tracking systems with time-ordered IDs, or creating content-addressed storage systems with deterministic hashes, this tool provides the flexibility and power you need. The UUID inspector lets you validate existing UUIDs, identify their version, and understand their properties - essential for debugging UUID-related issues and auditing codebases. With support for multiple output formats (standard, no hyphens, URN, and braces), case options, bulk generation of up to 1000 UUIDs at once, and instant copy-to-clipboard functionality, this is the most comprehensive free UUID tool available for developers. Every UUID is generated using cryptographically secure random number generation (crypto.getRandomValues), ensuring uniqueness and security for production use.
Beyond simple UUID generation, this tool educates developers on UUID best practices through comprehensive quick reference documentation, real-world use case examples, and detailed explanations of when to use each UUID version. Understanding the difference between random v4 UUIDs and timestamp-based v1 UUIDs can mean the difference between a scalable distributed system and a system with sorting and performance issues. Knowing when to use deterministic v5 UUIDs instead of v4 can prevent duplicate resource creation in idempotent API operations. RJL.io is committed to building developer tools that not only solve immediate problems but also teach best practices - and this RFC4122-compliant UUID generator exemplifies that mission by combining powerful functionality with educational content to make developers more effective.