README.md

👾 Konami Code (browser-only)

Tiny, lightweight, cross-browser compatible. Only 461 bytes minified!

Instructions

Copy & paste into a <script> tag, and modify line #16 with your own custom action!

konami-code.js

const KEY_DELAY = 2000; // Maximum time to allow in between key presses (Default: 2 seconds) 
const KONAMI_CODE = ['ArrowUp', 'ArrowUp', 'ArrowDown', 'ArrowDown', 'ArrowLeft', 'ArrowRight', 'ArrowLeft', 'ArrowRight', 'KeyB', 'KeyA'];

let keyBuffer = [];
let bufferTimeout;

window.addEventListener('keyup', (evt) => {
  clearTimeout(bufferTimeout);
  bufferTimeout = setTimeout(() => { keyBuffer = []; }, KEY_DELAY);

  const next = keyBuffer.length;
  if (evt.code === KONAMI_CODE[next]) {
    keyBuffer.push(evt.code);

    if (keyBuffer.length === KONAMI_CODE.length) {
      // Change this with your desired action
      alert('Konami Code successfully entered!');
    }
  } else {
    keyBuffer = [];
  }
});