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UUID.js - RFC-compliant UUID Generator for JavaScript

npm License


<!-- HTML5 -->
<script type="module">
  import { UUID } from "^5";
  const uuid = UUID.generate();
// Node.js
import { UUID } from "uuidjs";
const uuid = UUID.generate();
// TypeScript
import { UUID } from "uuidjs";
const str: string = UUID.generate();
const obj: UUID = UUID.genV4();
# Command-line
npx uuidjs


UUID.js is a JavaScript/ECMAScript library to generate RFC 4122 compliant Universally Unique IDentifiers (UUIDs). This library supports both version 4 UUIDs (UUIDs from random numbers) and version 1 UUIDs (time-based UUIDs), and provides an object-oriented interface to print a generated or parsed UUID in a variety of forms.


  • Generates version 4 UUIDs (UUIDs from random numbers) and version 1 UUIDs (time-based UUIDs)
  • Provides an object-oriented interface to print various string representations of a generated or parsed UUID
  • Utilizes a cryptographically secure pseudo-random number generator if available, whereas falling back to Math.random() otherwise
  • Appends extra random bits to compensate for the lower timestamp resolution of JavaScript than that required for version 1 UUIDs
  • Comes with a lot of test cases including format checks and statistical tests to maintain a high-quality code base

Usage Examples

Import UUID class:

import { UUID } from "uuidjs";
// or on browsers:
// import { UUID } from "^5";

UUID.generate() returns a version 4 UUID as a hexadecimal string.

// Create a version 4 UUID as a hexadecimal string
console.log(UUID.generate());   // fa84cf42-ffdf-4975-b42b-31ab5fb983eb

UUID.genV4(), UUID.genV1(), and UUID.parse() return a UUID object that has various fields and methods.

// Create a version 4 (random number-based) UUID object
const objV4 = UUID.genV4();

// Create a version 1 (time-based) UUID object
const objV1 = UUID.genV1();

// Create a UUID object from a hexadecimal string
const uuid = UUID.parse("a0e0f130-8c21-11df-92d9-95795a3bcd40");

// Get string representations of a UUID object
console.log(uuid.toString());   // "a0e0f130-8c21-11df-92d9-95795a3bcd40"
console.log(uuid.hexString);    // "a0e0f130-8c21-11df-92d9-95795a3bcd40"
console.log(uuid.hexNoDelim);   // "a0e0f1308c2111df92d995795a3bcd40"
console.log(uuid.bitString);    // "101000001110000 ... 1100110101000000"
console.log(uuid.urn);          // "urn:uuid:a0e0f130-8c21-11df-92d9-95795a3bcd40"

// Compare UUID objects
console.log(objV4.equals(objV1));   // false

// Get UUID version numbers
console.log(objV4.version); // 4
console.log(objV1.version); // 1

// Get internal field values in 3 different forms via 2 different accessors
console.log(uuid.intFields.timeLow);                // 2699096368
console.log(uuid.bitFields.timeMid);                // "1000110000100001"
console.log(uuid.hexFields.timeHiAndVersion);       // "11df"
console.log(uuid.intFields.clockSeqHiAndReserved);  // 146
console.log(uuid.bitFields.clockSeqLow);            // "11011001"
console.log(uuid.hexFields.node);                   // "95795a3bcd40"

console.log(uuid.intFields[0]);                     // 2699096368
console.log(uuid.bitFields[1]);                     // "1000110000100001"
console.log(uuid.hexFields[2]);                     // "11df"
console.log(uuid.intFields[3]);                     // 146
console.log(uuid.bitFields[4]);                     // "11011001"
console.log(uuid.hexFields[5]);                     // "95795a3bcd40"


Copyright (c) 2010-2023 LiosK

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.



See Also