MMS Media Requirements & Best Practices

This article outlines the supported media types, file size limits, formatting requirements, and creative best practices for sending MMS (Multimedia Messaging Service) messages through most mobile carriers. Following these guidelines increases the likelihood that your MMS messages are delivered successfully and appear clearly on all major devices.

Supported Media Types

The following image formats are widely supported for MMS:

• PNG
• JPEG / JPG
• GIF (static or animated)

Other file types (such as MP4, WebP, BMP, TIFF, and SVG) are not supported for MMS by mobile carriers. Unsupported formats may be blocked, fail to send, or appear corrupted on the recipient’s device.

If you upload an unsupported format, convert it to PNG or JPEG before sending. PNG is generally preferred for clarity; JPEG is preferred for large images when file size needs to be reduced.

PNG vs. JPEG

PNG

• Lossless quality – never blurry or distorted.
• Retains data after editing.
• Allows transparent backgrounds (but transparency is not recommended for MMS due to unpredictable rendering).

JPEG

• Smaller file sizes, especially for photographs.
• Easier to compress.
• Uses lossy compression, so repeated editing can cause blurriness.

Recommendation: Use PNG when possible. If an image is large and needs to be downsized significantly, a JPEG may produce a smaller file than PNG while maintaining acceptable quality.

File Size Limit

Most U.S. carriers enforce strict MMS size limits. To ensure deliverability:

All images and GIFs must be under 600 KB.

Sending an image larger than this limit may result in:

• Carrier compression that distorts or pixelates the image
• Failed delivery of the message
• Slow loading on recipients’ devices

Recommended Image Ratios & Dimensions

MMS images should not be extremely tall or wide. Mobile devices automatically scale media to fit the width of the message. Ratios beyond 9:16 or 16:9 may appear distorted.

Best option: Portrait (9:16), followed by Square (1:1). Portrait media renders consistently on most devices and rarely gets cropped.

GIF Length Recommendations

GIFs can technically be up to 60 seconds, but carriers often compress them heavily.

Recommended length: 6 seconds or less.

Shorter GIFs reduce file size, deliver more reliably, and appear clearer across devices.

Best Practices for MMS Media

Do:

• Use high color contrast. Helps avoid muddy or blended visuals after carrier compression.
• Ensure strong gradient contrast. Colors that are too similar may appear as flat blocks of color.
• Keep text large and readable. Small text may blur due to compression.

Don’t:

• Avoid transparent backgrounds. Carriers often replace transparency with random colors, causing unintended appearance.
• Avoid borders. Some iOS devices display borders off-center or cropped.
• Avoid opacity transitions in GIFs. These can introduce random colors and significantly increase file size.

Additional Recommendations

• Test media on multiple devices (iOS + Android) before sending to customers.
• Keep text minimal inside images — simpler designs compress better.
• Use solid backgrounds instead of gradients to ensure clarity after compression.
• For animated content, consider exporting as a short MP4 for channels that support it (though MMS does not).

Summary

To ensure the best MMS results, use PNG or JPEG files under 600 KB, follow recommended aspect ratios, avoid transparency and borders, and keep GIFs short. Adhering to these standards improves deliverability, reduces distortion, and ensures a consistent viewing experience across devices.