關於計算首屏時間
利用performance.timing
提供的數據:
通過DOMContentLoad
或者performance
來計算出首屏時間
// 方案一: document.addEventListener('DOMContentLoaded', (event) => { console.log('first contentful painting'); }); // 方案二: performance.getEntriesByName("first-contentful-paint")[0].startTime // performance.getEntriesByName("first-contentful-paint")[0] // 會返回一個 PerformancePaintTiming的實例,結構如下: { name: "first-contentful-paint", entryType: "paint", startTime: 507.80000002123415, duration: 0, };