Generating & Validating UUIDs

UUIDs (universally unique identifier) can be used to uniquely identify some object or data.

A random UUID can be generated using the builtin Web Cryptography API. This type of UUID is also known as UUID v4.

const myUUID = crypto.randomUUID();
console.log("Random UUID:", myUUID);

The standard library contains some more functions for working with UUIDs.

import * as uuid from "jsr:@std/uuid";

You can validate that a given string is a valid UUID.

console.log(uuid.validate("not a UUID")); // false
console.log(uuid.validate("6ec0bd7f-11c0-43da-975e-2a8ad9ebae0b")); // true

You can also generate a time-based (v1) UUID. By default this uses system time as the time source.

console.log(uuid.v1.generate());

SHA-1 namespaced (v5) UUIDs can also be generated. For this you need to specify a namespace and data:

const NAMESPACE_URL = "6ba7b810-9dad-11d1-80b4-00c04fd430c8";
const data = new TextEncoder().encode("deno.land");
console.log(await uuid.v5.generate(NAMESPACE_URL, data));

Run this example locally using the Deno CLI:

deno run https://examples.deno.land/uuids.ts

Additional resources:

Hashing ULID