elite-performance

极致性能

在达到 Core Web Vitals 目标的同时，保持动画流畅运行在 60fps。

快速参考

主题	参考文件
Vite 配置	vite-setup.md
动画性能	animation-performance.md
资源优化	asset-optimization.md
调试	debugging.md

---

性能预算（2026）

Core Web Vitals 目标

指标	良好	需改进	较差
LCP（最大内容绘制）	≤ 2.5s	≤ 4.0s	> 4.0s
INP（交互到下一次绘制）	≤ 200ms	≤ 500ms	> 500ms
CLS（累积布局偏移）	≤ 0.1	≤ 0.25	> 0.25

动画目标

指标	目标
帧率	60fps（16.67ms/帧）
帧预算	JS/布局 < 10ms
动画启动	响应时间 < 100ms
滚动卡顿	丢帧数为 0

Bundle 目标

资源	目标
初始 JS	< 100KB（gzip 压缩后）
初始 CSS	< 50KB（gzip 压缩后）
GSAP 核心	约 25KB（gzip 压缩后）
初始资源总计	< 200KB（gzip 压缩后）

---

GPU 加速属性

仅为这些属性添加动画

/* GPU composited - FAST */
transform: translateX() translateY() translateZ() scale() rotate() skew();
opacity: 0 to 1;
filter: blur() brightness() contrast();

/* Will trigger compositor layer */
will-change: transform, opacity;

绝不要为这些属性添加动画

/* Triggers layout - SLOW */
width, height
top, right, bottom, left
margin, padding
font-size
border-width

/* Triggers paint - SLOW */
background-color, color
border-color
box-shadow
text-shadow

transform 与 position

/* BAD - Triggers layout every frame */
.element {
  animation: moveLeft 1s;
}
@keyframes moveLeft {
  to {
    left: 100px;
  }
}

/* GOOD - GPU composited */
.element {
  animation: moveLeft 1s;
}
@keyframes moveLeft {
  to {
    transform: translateX(100px);
  }
}

---

快速提升性能的方法

1. 延迟加载首屏以下的内容

<img src="hero.jpg" alt="Hero" loading="eager" />
<img src="feature.jpg" alt="Feature" loading="lazy" />


<div class="lazy-section" data-component="heavy-animation">
  
</div>

2. 使用 content-visibility

/* Skip rendering off-screen sections */
.section {
  content-visibility: auto;
  contain-intrinsic-size: 0 500px; /* Estimated height */
}

3. 限制开销大的效果

/* Isolate animated sections */
.animated-section {
  contain: layout style paint;
}

/* Full containment for cards */
.card {
  contain: strict;
}

4. 在适当情况下减少动画

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

5. 优化滚动处理程序

// BAD - Fires on every scroll event
window.addEventListener("scroll", handleScroll);

// GOOD - Passive listener, no preventDefault
window.addEventListener("scroll", handleScroll, { passive: true });

// BETTER - Use ScrollTrigger (already optimized)
gsap.to(".element", {
  scrollTrigger: {/* ... */},
});

---

GSAP 性能

使用 gsap.context() 清理资源

// Prevents memory leaks
const ctx = gsap.context(() => {
  gsap.to(".element", { x: 100 });
  ScrollTrigger.create({/* ... */});
});

// On unmount
ctx.revert();

批量更新 ScrollTrigger

// Process multiple items efficiently
ScrollTrigger.batch(".item", {
  onEnter: (batch) =>
    gsap.to(batch, {
      opacity: 1,
      y: 0,
      stagger: 0.1,
    }),
});

使用 refreshPriority

// Control refresh order
ScrollTrigger.create({
  trigger: ".section",
  refreshPriority: -1, // Refresh after others
});

延迟创建 ScrollTrigger

// Don't create all at once
const createTrigger = (element) => {
  ScrollTrigger.create({
    trigger: element,
    start: "top 80%",
    onEnter: () => {
      // Create animation only when needed
      gsap.from(element, { opacity: 0, y: 50 });
    },
    once: true,
  });
};

// Create triggers as needed
gsap.utils.toArray(".section").forEach(createTrigger);

---

CSS 动画性能

高效的关键帧

/* GOOD - Only compositor properties */
@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* BAD - Triggers layout */
@keyframes slideIn {
  from {
    opacity: 0;
    margin-top: 30px;
  }
  to {
    opacity: 1;
    margin-top: 0;
  }
}

will-change 最佳实践

/* Apply just before animation */
.card {
  transition:
    transform 0.3s,
    opacity 0.3s;
}

.card:hover {
  will-change: transform;
}

/* Remove after animation */
.card.animating {
  will-change: transform, opacity;
}

/* Never do this globally */
/* * { will-change: transform; } NEVER! */

合成图层

/* Force new layer when needed */
.animated-element {
  transform: translateZ(0); /* or translate3d(0,0,0) */
}

/* Better: Use will-change temporarily */
.animating {
  will-change: transform;
}

---

加载策略

关键路径

<head>
  
  <style>
    /* Above-fold styles */
  </style>

  
  <link rel="preload" href="hero.webp" as="image" />
  <link rel="preload" href="font.woff2" as="font" crossorigin />

  
  <link
    rel="stylesheet"
    href="full.css"
    media="print"
    onload="this.media='all'"
  />
</head>

<body>
  

  
  <script src="gsap.min.js" defer></script>
  <script src="app.js" defer></script>
</body>

动态导入

// Load GSAP plugins only when needed
const loadScrollTrigger = async () => {
  const { ScrollTrigger } = await import("gsap/ScrollTrigger");
  gsap.registerPlugin(ScrollTrigger);
  return ScrollTrigger;
};

// Load on interaction or visibility
const section = document.querySelector(".scroll-section");
const observer = new IntersectionObserver(async ([entry]) => {
  if (entry.isIntersecting) {
    await loadScrollTrigger();
    initScrollAnimations();
    observer.disconnect();
  }
});
observer.observe(section);

渐进增强

// Check for animation support
const supportsAnimation = "animate" in document.documentElement;
const prefersReducedMotion = window.matchMedia(
  "(prefers-reduced-motion: reduce)",
).matches;

if (supportsAnimation && !prefersReducedMotion) {
  // Load animation library
  import("./animations.js");
} else {
  // Show final states immediately
  document.querySelectorAll(".animated").forEach((el) => {
    el.classList.add("animation-complete");
  });
}

---

内存管理

清理动画

// Store references for cleanup
const animations = [];
const scrollTriggers = [];

function initAnimations() {
  animations.push(gsap.to(".element", { x: 100 }));

  scrollTriggers.push(ScrollTrigger.create({ trigger: ".section" }));
}

function cleanup() {
  animations.forEach((anim) => anim.kill());
  scrollTriggers.forEach((st) => st.kill());
  animations.length = 0;
  scrollTriggers.length = 0;
}

// Or use gsap.context()
const ctx = gsap.context(() => {
  // All animations here
});

// Cleanup
ctx.revert();

SplitText 清理

const splits = [];

function initTextAnimations() {
  document.querySelectorAll(".split-text").forEach((el) => {
    const split = new SplitText(el, { type: "chars" });
    splits.push(split);

    gsap.from(split.chars, {
      opacity: 0,
      y: 20,
      stagger: 0.02,
    });
  });
}

function cleanup() {
  splits.forEach((split) => split.revert());
  splits.length = 0;
}

清理事件监听器

// Use AbortController for easy cleanup
const controller = new AbortController();

window.addEventListener("resize", handleResize, {
  signal: controller.signal,
});

window.addEventListener("scroll", handleScroll, {
  passive: true,
  signal: controller.signal,
});

// Cleanup all at once
function cleanup() {
  controller.abort();
}

---

调试清单

性能问题

1. 丢帧？

   • 检查 DevTools Performance 面板
   • 查找长任务（> 50ms）
   • 确认动画仅涉及合成器属性

2. 初始加载缓慢？

   • 检查 Network 瀑布图
   • 确认关键路径已优化
   • 检查 Bundle 大小

3. 内存泄漏？

   • 随时间检查 Memory 面板
   • 确认导航时会执行清理
   • 留意已分离的 DOM 节点

4. 布局抖动？

   • 在 Performance 面板中查找强制重排
   • 批量执行 DOM 读取/写入
   • 使用 transform 代替 position

快速检查

// Log animation frame rate
let lastTime = performance.now();
let frameCount = 0;

function measureFPS() {
  frameCount++;
  const now = performance.now();
  if (now - lastTime >= 1000) {
    console.log("FPS:", frameCount);
    frameCount = 0;
    lastTime = now;
  }
  requestAnimationFrame(measureFPS);
}
measureFPS();

// Detect layout thrashing
const originalGetComputedStyle = window.getComputedStyle;
window.getComputedStyle = function (...args) {
  console.trace("getComputedStyle called");
  return originalGetComputedStyle.apply(this, args);
};

如需了解全面的调试技巧，请参阅 debugging.md。

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资源

• web.dev Performance
• Chrome DevTools Performance
• GSAP Performance Tips
• CSS Triggers - 哪些属性会触发布局/绘制