网页加载速度测试

测试网页加载速度

// ==UserScript==
// @name 网页加载速度测试
// @author ChatGPT
// @version 3.1.3
// @description 测试网页加载速度
// @match *://*/*
// @run-at document-start
// @type bookmarklet
// @grant none
// @namespace https://greasyfork.org/users/452911
// ==/UserScript==

(function() {

  const loadTimeElement = document.createElement('span');
  
  loadTimeElement.style.cssText = `
    position: fixed; 
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: 10px; 
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.3);
    text-align: center;
    white-space: nowrap; 
    width: 220px;
    z-index: 9999;
    background-color: white;
    color: black;
  `;

  const startTime = performance.now();

  window.addEventListener('load', () => {
    const endTime = performance.now();
    const timeElapsed = endTime - startTime;
    
    loadTimeElement.innerText = `页面加载耗时 ${timeElapsed.toFixed(2)} ms`;
    
    document.body.appendChild(loadTimeElement);
    
    setTimeout(() => {
      loadTimeElement.remove(); 
    }, 1200);
  });
  
})();