Generate cryptographically secure, unique identifiers for your databases, API testing, and software development. Supports v1, v4, and bulk generation.
Open UUID GeneratorA UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. While it is technically possible for two UUIDs to be the same, the probability is so incredibly low that they are considered unique for all practical purposes. A standard UUID is represented by 32 hexadecimal digits, displayed in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters.
UUIDs are essential in modern software architecture because they allow distributed systems to generate identifiers independently without a central authority or coordination. This makes them perfect for primary keys in databases, session identifiers, and unique file names.
There are several "versions" of UUIDs, each generated using a different algorithm. Our generator supports the most commonly used ones:
Version 1 UUIDs are generated using the current timestamp and the MAC address of the computer generating the ID. Because they include the time, they are naturally "sortable" in the order they were created. However, they carry a small privacy risk as the MAC address can identify the hardware used.
Version 4 is the most popular type of UUID. It is generated using cryptographically strong random numbers. Out of the 128 bits, 122 bits are random. The chance of a collision is virtually zero, making it the default choice for most web applications and APIs.
A NIL UUID is a special case where all bits are set to zero: 00000000-0000-0000-0000-000000000000. It is often used as a placeholder or to represent a "null" state in systems that require a UUID-formatted string but don't have a specific record to point to.
While our online tool is great for quick tests and bulk generation, you'll often need to generate UUIDs programmatically.
import uuid
# Generate a UUID v4
my_uuid = uuid.uuid4()
print(my_uuid)// In modern browsers or Node.js 14.17+
const myUuid = crypto.randomUUID();
console.log(myUuid);// Using basic PHP
function generateUuidV4() {
$data = random_bytes(16);
$data[6] = chr(ord($data[6]) & 0x0f | 0x40);
$data[8] = chr(ord($data[8]) & 0x3f | 0x80);
return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}
echo generateUuidV4();Often, developers need more than one UUID for testing purposes or for seeding a database. The ToolForge UUID Generator allows you to generate up to 50 UUIDs at once. Simply select the quantity, choose the version, and click generate. You can then copy all of them to your clipboard with a single click.
For all practical intents, yes. While they are not guaranteed to be unique across all of time and space, the number of possible v4 UUIDs is 2^122 (approximately 5.3 followed by 36 zeros). You would need to generate billions per second for centuries to have a significant chance of a collision.
A NIL UUID (00000000-0000-0000-0000-000000000000) is a special constant value defined in the RFC 4122 specification. It is commonly used as a "null" or "uninitialized" value in software applications.
Yes. Our generator uses the standard browser Crypto API, which provides cryptographically secure random numbers. The UUIDs produced are compliant with RFC 4122 and are safe for use in production systems.
Absolutely. Our tool runs entirely in your browser using JavaScript. The UUIDs are never sent to our server, nor are they logged or tracked. Your data stays on your machine.
Fast, secure, and entirely client-side. No signup required.