UUID Generator
Generate cryptographically secure UUID v4 identifiers instantly. Create single or bulk UUIDs (up to 50 at once) for databases, APIs, and applications. All generation happens in your browser using secure random values.
A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems. Our free UUID v4 Generatorcreates cryptographically secure random identifiers perfect for database primary keys, API tokens, session IDs, file names, and distributed systems. UUID v4 uses random numbers, making collisions virtually impossible (1 in 2122 chance). This tool generates UUIDs entirely in your browser using the secure crypto.getRandomValues() API, ensuring your identifiers are never sent to any server. Generate single or bulk UUIDs instantly with no signup required.
Click "Generate UUID" to create unique identifiers
Secure & Private Generation
All UUIDs are generated directly in your browser using the cryptographically securecrypto.getRandomValues()API. No data is ever sent to any server. Your UUIDs are truly private and secure.
How to Use the UUID Generator
- Select the quantity of UUIDs you need using the input field (1-50) or click a quick-select button.
- Click "Generate UUID" to instantly create your unique identifiers.
- Copy individual UUIDs by hovering over any UUID and clicking the "Copy" button that appears.
- Copy all UUIDs at once using the "Copy All" button to get all identifiers separated by newlines.
- Regenerate anytime by clicking the generate button again for fresh UUIDs, or use "Clear" to reset.
What is UUID v4?
UUID v4 is one of five UUID versions defined in RFC 4122. Unlike versions 1, 3, and 5 which use timestamps, MAC addresses, or hashing, UUID v4 is purely random. This makes it ideal for scenarios where uniqueness matters but traceability doesn't.
Example UUID v4: f47ac10b-58cc-4427-a520-6b7e24f77c9d
The 4 indicates version 4. The a (8, 9, a, or b) indicates the variant.
Common Use Cases
Database Primary Keys
Unique identifiers for records in SQL and NoSQL databases
API Request IDs
Track requests across microservices and distributed systems
Session & Token IDs
Secure, unguessable session identifiers and auth tokens
File & Asset Names
Unique names for uploads, preventing collisions and overwrites
Analytics Events
Track unique events, conversions, and user interactions
Idempotency Keys
Prevent duplicate processing in payment and order systems
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Frequently Asked Questions
What is a UUID and why should I use one?▼
A UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across all devices and time. UUIDs are used when you need identifiers that won't collide, even when generated by different systems without coordination. They're essential for distributed databases, microservices, offline-first apps, and any system where centralized ID generation isn't practical.
How random is UUID v4? Can there be collisions?▼
UUID v4 has 122 random bits (6 bits are fixed for version and variant). This means there are 2122 (about 5.3 × 1036) possible UUIDs. To have a 50% chance of a collision, you'd need to generate about 2.71 × 1018 UUIDs. For practical purposes, UUID v4 collisions are virtually impossible—you're more likely to be struck by a meteorite while holding a winning lottery ticket.
What's the difference between UUID and GUID?▼
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are essentially the same thing. UUID is the term used in RFC 4122 and most open-source/Unix contexts, while GUID is Microsoft's term used in Windows and .NET. They follow the same format and can be used interchangeably.
Is crypto.getRandomValues() better than Math.random()?▼
Yes, significantly. Math.random() uses a pseudo-random number generator (PRNG) that can be predictable and isn't suitable for security-sensitive applications.crypto.getRandomValues() uses the operating system's cryptographic random number generator, providing true randomness suitable for cryptographic operations, secure tokens, and UUIDs. This tool exclusively uses crypto.getRandomValues().
Can I use UUIDs as database primary keys?▼
Yes, UUIDs are commonly used as database primary keys, especially in distributed systems. Benefits include no coordination needed between servers, ability to generate IDs client-side, and no information leakage about record count. However, be aware that UUID v4's randomness can cause index fragmentation in some databases. Consider UUID v7 (time-ordered) or ULID for better index performance if this is a concern.
Frequently Asked Questions
❓ Is this tool free?
Yes! All our tools are completely free. No registration, no hidden charges, no ads. Just open and use.
🔒 Is my data safe?
Absolutely. All calculations happen in your browser. We don't store, send, or track any of your data. Everything is processed locally on your device.
📱 Can I use this on mobile?
Yes! All our tools are fully responsive and work perfectly on smartphones, tablets, and desktops.
🌐 Do I need internet?
No! Once the page loads, you can use the tool completely offline. All calculations happen in your browser without any server connection.