Why your media files should stay under 2MB
Flexmail limits media file uploads to 2MB per file. This might feel restrictive if you're used to working
with high-resolution images, but the limit exists for concrete reasons that affect how your emails reach and are experienced by your contacts.
Why the limit exists
Email loading time
Most contacts read email on mobile connections. An image that loads instantly on your desktop can take several seconds on a slower mobile network, and most readers abandon an email that takes too long to load. Images optimised for email (typically 50–300KB) load in under a second even on slower connections.
Email client behaviour
Many email clients automatically clip messages that exceed a certain total size. Gmail clips messages over 102KB, which means a heavy email may not display in full without the reader manually choosing to load the rest. Large embedded images are a leading cause of message clipping. Well-optimised images are the most straightforward way to keep your total email size manageable.
Storage and performance
The media library is designed for email hosting, fast CDN delivery, consistent uptime, and reliable URLs at the dimensions emails actually use. It's not a general-purpose storage system for high-resolution source files.
How to get your images under 2MB
Resize the image first
Email images don't need to be print-quality. A standard email layout is 600px wide. An image wider than 1200px (for 2x/Retina displays) is more than you need. Resize images to the actual dimensions they'll appear at in your email before uploading.
Use the right file format
- JPEG, best for photographs. Use 80–85% quality for a good balance of file size and visual quality.
- PNG, best for images with transparency or sharp edges (logos, graphics). Use PNG-8 instead of PNG-24 where colour depth allows.
- GIF, for animated images. Keep animations short and limit the colour palette.
Use a compression tool
Tools like Squoosh (squoosh.app), TinyPNG (tinypng.com), or ImageOptim (Mac) can reduce file sizes by 50–80% with minimal visible quality loss. Run your images through one of these tools before uploading to Flexmail.
Common mistakes to avoid
- Uploading the original camera or design export file without resizing first. Source files are almost always larger than needed for email.
- Using PNG for photographs. JPEG at 80% quality produces far smaller files than PNG for photographic content with no meaningful quality difference.
- Not compressing animated GIFs. A 3MB animated GIF can typically be reduced to under 500KB with tools like Ezgif without any noticeable quality loss.
Next steps
- See "Media library" for how to upload and organise your files.
- See "Add an image" for how to insert images into your messages.
- See "Animated images in emails" for GIF-specific guidance on file size and email client support.