2026 Current
WebP and AVIF have zero support in email clients. Despite web adoption, email remains locked to JPG, PNG, and GIF. APNG has limited support in Apple Mail only.
2026 Image Format Support Matrix
Supported: JPG ✓, PNG ✓, GIF ✓ (all major clients). Limited support: APNG ✓ (Apple Mail only). Not supported: WebP ✗, AVIF ✗, SVG ✗.
Why WebP Doesn't Work in Email
WebP is the modern image format on the web, but email clients haven't adopted it. Only Apple Mail supports WebP, making it unreliable. Stick to PNG and JPG for universal compatibility.
Image Blocking Reality in 2026
Most email clients load images by default in 2026. Corporate firewalls still block images, but this is less common. Always include alt text and meaningful fallback text in case images don't load.
ALT Text & Accessibility
Provide descriptive alt text for meaningful images. Use `alt=""` for decorative images. Alt text is essential for accessibility (EAA 2025 requirement) and serves as fallback when images are blocked.
Image-to-Text Ratio & Spam Filters
Emails with too many images and minimal text are flagged as spam. Maintain a 60:40 text-to-image ratio. Include meaningful body text in your template.
Retina (@2x) Image Sizing
Create images at 2x the display size (600x600px display size = 1200x1200px source). Set width and height attributes to the display size. Most email clients handle retina scaling automatically.
GIF Animation & Fallbacks
GIF animation is supported in most modern email clients. Outlook 2007-2019 doesn't support animation; use the first frame as a static fallback. Keep GIF file sizes under 100KB to avoid blocking.
Background Images & VML for Outlook
CSS background images work in some clients but not Outlook. Use VML (Vector Markup Language) with `