What image formats are best for email (JPG, PNG, GIF, SVG)?

Format choice depends on image content. JPEG: Best for photographs and complex images with many colors. Lossy compression keeps file sizes manageable. PNG: Best for graphics, logos, and images needing transparency. Larger files but lossless quality. GIF: Best for simple animations and graphics with limited colors (256 max). SVG: Avoid in email-very limited support.

Practical guidance: Photos → JPEG (60-80% quality, progressive encoding). Logos/icons → PNG (use PNG-8 for simple graphics, PNG-24 for transparency). Simple animations → GIF (keep frames and colors minimal for file size). Never use SVG in email-most clients don't render it.

File size trumps format purity. A well-optimized JPEG beats an unoptimized PNG every time. Use tools like TinyPNG, ImageOptim, or Squoosh to compress images before embedding. Aim for total email weight under 100KB where possible.