Choosing the right image format is essential for optimal web performance. Here's a comprehensive guide:

JPEG (Joint Photographic Experts Group):
- Best for photographs and complex images
- Uses lossy compression
- No transparency support
- Universal browser support

JPEG is ideal for photographs

PNG (Portable Network Graphics):
- Best for graphics, logos, and images with transparency
- Uses lossless compression
- Supports transparency and alpha channels
- Larger file sizes than JPEG

WebP (Web Picture Format):
- Modern format developed by Google
- 25-35% smaller than JPEG
- Supports both lossy and lossless compression
- Supports transparency
- Limited browser support (growing)

AVIF (AV1 Image File Format):
- Next-generation format
- 50% smaller than JPEG
- Excellent compression efficiency
- Very limited browser support

GIF (Graphics Interchange Format):
- Best for simple animations
- Limited color palette (256 colors)
- Large file sizes for static images
- Universal support

Choose the format based on your content type, browser support requirements, and file size constraints.