This post goes over how to generate a SHA-256 hexadecimal hash using Node.js and JavaScript in the browser:

• Node.js
• Browser

Node.js

To generate a SHA-256 hash in Node.js using crypto:

const { createHash } = require('crypto');

function hash(string) {
  return createHash('sha256').update(string).digest('hex');
}

Usage:

console.log(hash('foo')); // '2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'

Demo:

Browser

To generate a SHA-256 hash in the browser using SubtleCrypto:

function hash(string) {
  const utf8 = new TextEncoder().encode(string);
  return crypto.subtle.digest('SHA-256', utf8).then((hashBuffer) => {
    const hashArray = Array.from(new Uint8Array(hashBuffer));
    const hashHex = hashArray
      .map((bytes) => bytes.toString(16).padStart(2, '0'))
      .join('');
    return hashHex;
  });
}

Or written in async/await:

async function hash(string) {
  const utf8 = new TextEncoder().encode(string);
  const hashBuffer = await crypto.subtle.digest('SHA-256', utf8);
  const hashArray = Array.from(new Uint8Array(hashBuffer));
  const hashHex = hashArray
    .map((bytes) => bytes.toString(16).padStart(2, '0'))
    .join('');
  return hashHex;
}

Usage:

hash('foo').then((hex) => console.log(hex)); // '2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'

Demo: