Images

Web image formats, optimization, and responsive techniques

Image Formats

Coming soon: Understanding when to use each image format.

Raster Formats

  • JPEG - Lossy compression for photographs
  • PNG - Lossless with alpha transparency
  • GIF - Limited colors, simple animations
  • WebP - Modern format, superior compression
  • AVIF - Next-gen format, best compression

Vector Formats

  • SVG basics and syntax
  • Inline SVG vs external files
  • SVG optimization
  • Styling SVG with CSS
  • SVG animations

Responsive Images

Coming soon: Serve the right image for every device.

  • The srcset attribute
  • The sizes attribute
  • Resolution switching
  • Art direction with picture element
  • Source selection and format fallbacks
  • Device pixel ratio (DPR)

Optimization

Coming soon: Make images load faster.

  • Compression techniques
  • Image dimensions and sizing
  • Lazy loading with loading="lazy"
  • Eager loading for critical images
  • Image CDNs and on-the-fly optimization
  • Progressive JPEG
  • Tools: ImageOptim, Squoosh, Sharp

Accessibility

Coming soon: Make images accessible to everyone.

  • Alt text best practices
  • Decorative vs informative images
  • Complex images and long descriptions
  • Color contrast in images
  • Images of text (avoid them)