Best Image Format for Email Newsletter Images
JPG is the best image format for email newsletter images. Email client support for newer formats like WebP and AVIF is unreliable, making JPG the only safe choice for photos in email campaigns. PNG is the right choice for graphics, logos, and any newsletter image requiring transparency or sharp text. Together, JPG and PNG cover every newsletter image need.
Email is the most format-constrained environment in digital publishing. Gmail, Outlook, Apple Mail, Yahoo Mail, and dozens of smaller clients all render images differently. An image that displays perfectly in Gmail may be blocked, distorted, or broken in Outlook. Your format choice needs to work everywhere, and that means sticking with proven formats.
Here is the format strategy for every type of newsletter image and platform-specific tips for popular email marketing tools.
Why WebP Does Not Work in Email
Despite WebP being the best format for web images, it is not suitable for email newsletters. Gmail web client supports WebP display, but the Outlook desktop app, many corporate email systems, and several mobile email clients do not render WebP images. Some clients will show a broken image icon. Others will display nothing at all.
Email design follows a principle of least common denominator. If even 5% of your subscribers cannot see an image, that is thousands of missed impressions per campaign. JPG and PNG have near-100% email client support, making them the only practical choices.
JPG for Newsletter Photos
Use JPG for all photographic images in newsletters: product photos, team headshots, event coverage, hero images, and lifestyle photography.
- Quality setting: 80-85. Email platforms re-compress images during sending, so start high but not wasteful.
- Width: 600-700 pixels for full-width images (standard email content width). 1200-1400 pixels if your template is retina-optimized.
- File size target: Under 200KB per image. Under 100KB is ideal. Large images slow delivery and may trigger spam filters.
- Color space: sRGB only. CMYK or Adobe RGB images may display with unexpected color shifts in email clients.
- Total email weight: Keep total email size under 1-2MB including all images. Campaigns over 2MB may be clipped (Gmail clips emails over 102KB of HTML).
PNG for Newsletter Graphics
Use PNG for newsletter images that contain text, logos, buttons, icons, diagrams, or any element requiring sharp edges or transparency.
- Logos and brand marks: PNG with transparent background so they work on any email template background color.
- Call-to-action buttons: While HTML/CSS buttons are preferred, image-based CTA buttons should be PNG for sharp text rendering.
- Infographics and charts: PNG preserves the readability of labels, legends, and data annotations.
- Decorative dividers and borders: PNG for simple graphics. Consider CSS borders instead where possible.
- Icons: PNG at 2x display size for Retina clarity. A 24x24 display icon should be 48x48 pixels in the file.
Email Platform-Specific Tips
Each email marketing platform handles images slightly differently. Understanding these differences helps you optimize for your tool.
- Mailchimp: Automatically compresses images during upload. Upload at quality 90+ to compensate for re-compression. Supports JPG, PNG, and GIF. Auto-generates retina variants.
- Constant Contact: Compresses uploaded images. Same advice: upload high quality. Recommends images under 1MB.
- Klaviyo: Hosts images on its CDN. Upload high-quality source files. Klaviyo handles delivery optimization.
- HubSpot: Similar to Mailchimp. Upload high quality, let the platform optimize. HubSpot CDN serves images quickly.
- Sendinblue (Brevo): Supports image hosting. Keep individual image files under 500KB for reliable delivery.
Handling iPhone HEIC Photos for Newsletters
Marketing teams often receive event photos, product shots, or behind-the-scenes content captured on iPhones in HEIC format. HEIC cannot be used in email newsletters. The photos must be converted to JPG before use.
imageconvert.co converts HEIC to JPG directly in your browser. This is especially useful for marketing teams that receive photos from non-technical stakeholders who send HEIC files without realizing the compatibility limitations. Drop the files, convert, and download JPGs ready for your newsletter platform.
Frequently Asked Questions
Can I use WebP images in email newsletters?
No, not reliably. While Gmail web displays WebP, Outlook, many mobile clients, and corporate email systems do not support it. Use JPG for photos and PNG for graphics to ensure images display correctly for all subscribers.
What is the ideal image width for email newsletters?
600-700 pixels for standard templates. For retina-optimized templates, use 1200-1400 pixels wide and let the email client scale down for display. Always test in multiple email clients to verify rendering.
How do I reduce newsletter email file size?
Compress JPG images to quality 80-85. Limit total images to 3-5 per email. Use HTML and CSS for buttons and backgrounds instead of images. Keep each image under 200KB and total email under 1-2MB.
Should I use GIF for newsletter images?
GIF is appropriate for simple animations in newsletters (product demos, attention-grabbing hero images). Keep animated GIFs under 500KB and under 5 seconds. For static images, never use GIF. It is limited to 256 colors and produces larger files than JPG or PNG.
Why do my newsletter images look blurry on phones?
Most phones have 2x or 3x pixel density displays. If your images are sized at 1x the display width (e.g., 600px for a 600px-wide email), they look blurry on Retina screens. Upload images at 2x the display width (1200px) and let the email client scale them down for sharp rendering.