Image Optimization Best Practices

Guidelines for optimizing images in web applications.

Image Formats

Modern Formats

• WebP: Excellent compression with good browser support
• AVIF: Next-generation format with superior compression
• JPEG XL: Emerging format with advanced features

Traditional Formats

• JPEG: Best for photographs and complex images
• PNG: Ideal for images with transparency
• SVG: Perfect for icons and simple graphics

Optimization Techniques

Compression

• Use appropriate quality settings (80-85% for JPEG)
• Apply lossless compression when possible
• Consider progressive JPEG for large images

Responsive Images

• Implement srcset for different screen sizes
• Use picture element for art direction
• Provide fallbacks for older browsers

Implementation

Loading Strategies

• Implement lazy loading for below-the-fold images
• Use intersection observer for performance
• Provide placeholder images during loading

CDN and Caching

• Use image CDNs for automatic optimization
• Implement proper caching headers
• Consider image transformation services