UUID Generator Online
Generate UUID v4 Instantly
Free UUID v4 generator online. Generate single or bulk UUIDs for databases, APIs, and distributed systems instantly. No sign-up required.
Generate UUIDs NowFree forever · No account needed · Works offline
Everything You Need in a UUID Generator
Generate RFC 4122 compliant UUID v4 identifiers instantly. Bulk generation, multiple formats, and one-click copy.
Instant Generation
Generate UUID v4 identifiers in milliseconds. Click once and get a new UUID instantly.
One-Click Copy
Copy any UUID to clipboard instantly. No manual selection or keyboard shortcuts needed.
Bulk Generator
Generate up to 100 UUIDs at once for database seeding, testing, and batch operations.
Cryptographically Secure
Uses the Web Crypto API for true randomness — the same standard used by secure applications.
Multiple Formats
Get UUIDs in uppercase, lowercase, or without hyphens to match your system's requirements.
RFC 4122 Compliant
All generated UUIDs conform to the RFC 4122 UUID v4 specification.
How to Generate a UUID Online — 2 Steps
Open the Tool
Click the button above to open the UUID Generator. No sign-up or installation required.
Set Quantity
Choose how many UUIDs you need — from 1 to 100. Then click Generate.
Copy & Use
Click Copy next to any UUID or copy all at once to use in your project.
Common Use Cases for UUID Generator
UUIDs are used everywhere in modern software development. Here's how developers use our UUID generator.
Database Primary Keys
Use UUIDs as primary keys in PostgreSQL, MySQL, MongoDB, or any database to avoid ID conflicts across distributed systems.
API Request Tracing
Assign unique trace IDs to API requests for logging, debugging, and distributed tracing across microservices.
Session Tokens
Generate secure, unpredictable session identifiers for user authentication and session management.
File Naming
Create unique filenames for uploaded files to prevent overwrites and collisions in cloud storage systems.
Testing & Mocking
Populate test databases with unique identifiers for unit tests, integration tests, and mock data generation.
Event Tracking
Assign unique IDs to analytics events, user actions, and system events for accurate tracking.
Frequently Asked Questions
What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify objects in computer systems. UUID v4 is the most common version and uses random or pseudo-random numbers, making collisions virtually impossible.
Is this UUID generator free?
Yes, completely free. No sign-up, no account, no limits. Generate as many UUIDs as you need.
Are the generated UUIDs truly unique?
UUID v4 uses cryptographic randomness to generate identifiers. The probability of collision is astronomically low — approximately 1 in 5.3 × 10^36.
What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's term for UUID. They are functionally identical — both are 128-bit identifiers formatted as 32 hex digits in groups separated by hyphens.
Can I generate bulk UUIDs?
Yes. The UUID generator on WebToolsBox allows you to generate multiple UUIDs at once — from 1 to 100 at a time. Each UUID is displayed on a separate line for easy copying.