Website Image Optimization Checklist
Use this comprehensive checklist to ensure every image on your website is optimized for performance, SEO, and user experience. Work through each section systematically.
1️⃣ Compression & Quality
- ☐Compress all images - Reduce file size by 50-80%
- ☐Quality 70-85% - Sweet spot for most web images
- ☐Convert to WebP - 30% smaller than JPEG
- ☐Test visually - No visible artifacts at actual size
2️⃣ Dimensions & Sizing
- ☐Resize to display size - Match actual dimensions shown
- ☐Max 1920px width - No web image needs more
- ☐Thumbnails 300-400px - Small files for small slots
- ☐Use srcset - Serve different sizes to different devices
3️⃣ Format Selection
Use JPEG for:
- Photographs
- Complex images with many colors
- Gradient backgrounds
- Any image without transparency
Use PNG for:
- Logos and icons
- Screenshots
- Images with transparency
- Graphics with sharp edges
4️⃣ SEO & Accessibility
- ☐Alt text on all images - Descriptive, keyword-relevant
- ☐Descriptive filenames - red-running-shoes.jpg not IMG_001.jpg
- ☐Width and height attributes - Prevents layout shift (CLS)
- ☐Image sitemap - Help Google find all images
5️⃣ Performance
- ☐Lazy loading - Load images only when scrolled into view
- ☐Preload hero image - For above-fold content
- ☐CDN usage - Serve from edge locations globally
- ☐Browser caching - Set long cache headers for images
6️⃣ Responsive Images
- ☐srcset attribute - Multiple image sizes for different screens
- ☐sizes attribute - Define image slot sizes at different breakpoints
- ☐picture element - Serve different formats (WebP/JPEG)
- ☐Mobile-first sizing - Start with smallest, scale up
7️⃣ Maintenance
- ☐Audit quarterly - Check for new unoptimized images
- ☐Test with PageSpeed - Verify Core Web Vitals
- ☐Monitor lighthouse scores - Track performance over time
- ☐Keep originals - Uncompressed masters for re-editing
📊 Target File Sizes
| Image Type | Target Size |
|---|
| Hero Banner | Under 200 KB |
| Featured Image | Under 100 KB |
| Content Image | Under 80 KB |
| Thumbnail | Under 30 KB |
| Icon / Logo | Under 10 KB |
Optimize Your Website Images
Use this checklist to audit and improve your image performance.
Compress Images NowThis tool performs compression locally in your browser. Your images are not uploaded to any server.
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