Email Image Optimization

Choosing the Right Format

• JPEG: Best for photographs. Good compression with acceptable quality. Use for product photos and lifestyle imagery.
• PNG: Best for graphics with transparency, screenshots, or images with text. Larger file sizes than JPEG but better for sharp edges.
• GIF: Use sparingly for simple animations. Large file sizes and limited colors make them impractical for complex content.
• SVG: Generally avoid in email due to poor client support.

File Size Guidelines

Total email size should stay under 100KB for optimal deliverability. Individual images should be as small as possible while maintaining acceptable quality. Compress images before including them in emails.

Dimension Best Practices

• Maximum width of 600-700px for the email container
• Hero images: 600px wide maximum
• Product images: 200-300px wide typically
• Always specify both width and height attributes
• Use retina images (2x) where practical for sharp display

Alt Text Strategy

Every image needs alt text. When images are blocked (common default behavior), alt text conveys the image's purpose. Write descriptive alt text that makes sense in context.

Image Blocking

Many email clients block images by default. Your email must make sense without images. Use real HTML text for critical content, not text embedded in images. Design with image blocking in mind.

Hosting and URLs

• Use absolute URLs (https://...) not relative paths
• Host images on reliable, fast servers
• Use HTTPS to avoid security warnings
• Consider CDN hosting for global audiences

Optimized Images with AI

Sequenzy generates templates with properly optimized image recommendations and ensures your emails work with or without images loading.