Why Image Optimization Matters
Faster Page Load
Images account for 50-80% of page weight. Optimization dramatically improves load times.
Better SEO
Google ranks faster sites higher. Optimized images improve Core Web Vitals.
Reduced Bandwidth
Lower file sizes mean less data usage for mobile users and lower hosting costs.
Better UX
Fast-loading images keep users engaged and reduce bounce rate.
Image Formats Comparison
- Best for: Photographs, complex images
- Compression: Lossy (quality vs size trade-off)
- Transparency: No
- Browser Support: 100%
- ✓ Use at 80-85% quality for best balance
- Best for: Graphics, logos, text
- Compression: Lossless (no quality loss)
- Transparency: Yes
- Browser Support: 100%
- ✓ Larger files than JPEG
- Best for: Everything (modern browsers)
- Compression: Lossy & lossless
- Transparency: Yes
- Browser Support: 97%+
- ✓ 25-35% smaller than JPEG/PNG
- Best for: High-quality photos
- Compression: Lossy & lossless
- Transparency: Yes
- Browser Support: 85%+
- ✓ 50% smaller than JPEG
Compression Best Practices
- 1.Choose the right format
WebP for most cases, PNG for transparency with text/graphics, JPEG for old browser support
- 2.Use appropriate quality
80-85% quality is the sweet spot - visually similar to 100% but much smaller
- 3.Resize before compressing
Don't serve 4000px images when you only need 1200px. Resize first for better results.
- 4.Strip metadata
Remove EXIF data unless needed - can save 10-50KB per image
- 5.Test visual quality
Always preview compressed images before deploying to ensure acceptable quality
- 6.Use progressive rendering
Progressive JPEGs load gradually, providing better perceived performance
Web Performance Tips
✓Lazy loading: Load images only when visible
✓Responsive images: Serve different sizes for different screens
✓CDN delivery: Serve images from edge locations
✓Cache headers: Set long expiry for immutable images
✓Preload critical images: Above-fold images load first
✓Use blur placeholders: Show preview while loading
✓Optimize thumbnails: Use tiny versions for grids/lists
✓Monitor Core Web Vitals: Track LCP, CLS metrics
Common Optimization Mistakes
✗Using PNG for photographs
✗Compressing already compressed images
✗Serving full-size images to mobile
✗Over-compressing (quality below 70%)
✗Not testing on real devices
✗Ignoring format compatibility
✗Forgetting alt text (SEO/a11y)
✗Not monitoring file sizes
💡 Pro Tips
- •Quality sweet spot: JPEG at 80-85% is indistinguishable from 100% but 40-60% smaller
- •WebP adoption: Use with JPEG fallback for maximum compatibility
- •AVIF for hero images: Latest format delivers stunning quality at tiny sizes
- •Batch processing: Optimize all images at once to save time
- •Client-side tools: No server upload means privacy and speed
- •Monitor savings: Track before/after sizes to measure impact