Performance7 min read
2025年にウェブパフォーマンスのために画像を最適化する方法
この記事は英語で利用可能です。インターフェースは日本語に翻訳されています。
Images typically account for 50-75% of a web page's total size. Optimizing them is the single most impactful thing you can do for page speed.
Key Metrics
Optimization Checklist
1. Choose the right format: WebP for photos, SVG for icons, PNG for transparency
2. Compress aggressively: Use quality 80-85% for JPEG/WebP
3. Resize to display dimensions: Don't serve 4000px images in 800px containers
4. Use responsive images: Serve different sizes for different viewports
5. Lazy load below-fold images: Only load images when they're about to enter the viewport
6. Use CDN: Serve images from edge locations close to users
Tools You Can Use
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