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

Website Image Optimization Checklist

1️⃣ Compression & Quality

2️⃣ Dimensions & Sizing

3️⃣ Format Selection

Use JPEG for:

Use PNG for:

4️⃣ SEO & Accessibility

5️⃣ Performance

6️⃣ Responsive Images

7️⃣ Maintenance

📊 Target File Sizes

Optimize Your Website Images