What is the difference between UUID v1, v4, and other versions?

UUID v1 uses timestamp and MAC address, making it predictable and potentially revealing hardware information. UUID v4 uses random numbers, offering better privacy and unpredictability. UUID v5 uses namespace and name hashing for reproducible UUIDs. This tool generates UUID v4, which is recommended for most modern applications due to its strong randomness and privacy characteristics.

Are UUIDs truly unique?

UUID v4 uses cryptographically secure random numbers via the Web Crypto API. While theoretically two identical UUIDs could be generated, the probability is astronomically low (approximately 1 in 5.3 × 10^36 or 1 in 2^122) that it is effectively impossible in practice. You can safely use UUIDs without worrying about collisions.

Is this UUID generator free?

Yes, our UUID generator is completely free with no limits on usage. You can generate unlimited UUIDs without signing up, paying anything, or dealing with advertisements. All processing happens locally in your browser for maximum privacy and speed.

What are UUIDs used for?

UUIDs are widely used as database primary keys, distributed system identifiers, session tokens, file names, API request tracking, message queue identifiers, and anywhere you need globally unique identifiers without a central authority. They are especially valuable in distributed systems where multiple nodes need to generate unique IDs independently.

Can UUIDs be predicted or guessed?

UUID v4 (generated by this tool) cannot be predicted or guessed because it uses cryptographically secure random number generation. Unlike sequential IDs or timestamp-based UUIDs, v4 UUIDs provide no information about when or where they were created, making them suitable for security-sensitive applications.

Is my data secure when using this generator?

Yes, all UUID generation happens entirely in your browser using the native crypto.randomUUID() function. No data is sent to any server, stored anywhere, or tracked in any way. Your generated UUIDs are completely private and only exist on your device.

How many UUIDs can I generate at once?

This tool allows you to generate 1, 5, 10, or 25 UUIDs at once. All UUIDs are generated instantly using your browser's built-in cryptographic functions. You can copy them individually or all at once, and generate new batches as many times as needed without any restrictions.

UUID Generator

Generate random UUIDs (v4) instantly. Your data never leaves your browser.

Number of UUIDs

Uppercase

Generated UUIDs

Related Tools

Password Generator

Create secure passwords

Hash Generator

Generate MD5, SHA hashes

How to Use

1. Select how many UUIDs you want to generate (1, 5, 10, or 25)
2. Toggle uppercase if you prefer uppercase UUIDs
3. Click "Copy" next to any UUID to copy it individually
4. Click "Copy All" to copy all UUIDs at once (separated by newlines)
5. Click "Generate New" to create new UUIDs

What is a UUID?

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit identifier that is unique across both space and time. UUIDs are commonly used in software development to identify database records, distributed systems components, session IDs, and more.

About UUID Version 4

This tool generates UUID v4 (random) identifiers. UUID v4 uses random or pseudo-random numbers to generate the identifier. The format consists of 32 hexadecimal digits displayed in five groups separated by hyphens: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where "4" indicates the version and "y" is one of 8, 9, A, or B.

FAQ

Are these UUIDs truly unique?

UUID v4 uses cryptographically secure random numbers via the Web Crypto API. While theoretically two identical UUIDs could be generated, the probability is so low (1 in 2^122) that it is effectively impossible in practice.

Is this generator secure?

Yes, UUIDs are generated using the browser's native crypto.randomUUID() function, which uses cryptographically secure random number generation. All processing happens locally in your browser.

Can I use these UUIDs in production?

Absolutely! The UUIDs generated by this tool are fully compliant with RFC 4122 and suitable for any production use case including database primary keys, API identifiers, session tokens, and more.