UUID Generator
Generated UUIDs (0)
Click "Generate" to create UUIDs
UUID v4: These are randomly generated UUIDs using cryptographically strong random values. Each UUID has a 1 in 5.3×10³⁶ chance of collision, making them practically unique for all purposes.
About UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems. This tool generates UUID version 4 (random UUIDs) using cryptographically strong random values from your browser's crypto API. UUIDs are commonly used as database primary keys, session identifiers, file names, and in distributed systems where unique identification is needed without central coordination.
How to Use
- Set the quantity of UUIDs you want to generate (1-1000).
- Choose your preferred format: lowercase or uppercase.
- Toggle "Include Hyphens" to control the UUID format.
- Click "Generate" to create new UUIDs or "Add More" to add to existing ones.
- Click the copy icon next to any UUID to copy it, or use "Copy All" for all UUIDs.
- Use the regenerate icon to create a new UUID in place, or the trash icon to remove one.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. It's typically displayed as 32 hexadecimal digits in five groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000).
What is UUID v4?
UUID version 4 (v4) generates random UUIDs using cryptographically strong random numbers. Unlike other versions that may use timestamps or MAC addresses, v4 UUIDs are entirely random, making them ideal for most use cases where true randomness and privacy are desired.
Are these UUIDs truly unique?
While theoretically possible to generate duplicate UUIDs, the probability is so low (1 in 5.3×10³⁶) that they are considered unique for all practical purposes. You would need to generate billions of UUIDs per second for many years to have even a tiny chance of a collision.
When should I use UUIDs?
UUIDs are perfect for: database primary keys (especially in distributed systems), session identifiers, file or object names, temporary identifiers, API keys, transaction IDs, and any situation where you need a unique identifier without a centralized authority to generate them.
Should I use hyphens or not?
The standard UUID format includes hyphens (8-4-4-4-12 format). Use hyphens for better readability and standard compliance. Remove hyphens if you need to save space, use the UUID in a URL, or integrate with systems that expect compact identifiers.
What's the difference between uppercase and lowercase?
Functionally, there is no difference—UUIDs are case-insensitive. Choose based on your coding standards or system requirements. Lowercase is more common in web development, while uppercase might be preferred in some database systems.
Can I generate UUIDs offline?
Yes! This tool uses your browser's built-in crypto.randomUUID() function or a cryptographically secure fallback. All UUID generation happens entirely in your browser without any network requests, so it works perfectly offline.
Is it safe to use these UUIDs in production?
Absolutely! These UUIDs are generated using cryptographically secure random number generators (crypto.randomUUID() or crypto.getRandomValues()). They are suitable for production use, including security-sensitive applications. However, never use UUIDs alone as authentication tokens—always use proper authentication mechanisms.