MMS messages are routed through Carrier Gateways (MMSC) to reach mobile subscribers. Each gateway has a maximum message size, which varies across carriers. The file size depends on the destination mobile device and the carrier network. We provide an MMS content transcoding service for our Short Code product to help optimize the size of MMS content. This service automatically resizes content based on mobile device and carrier gateway limitations, reducing deliverability issues when sending content that is too large for the recipient's network.
Most mobile display content in a portrait orientation, making it essential to optimize content for a vertical layout. MMS images should be sized in portrait or square dimensions, as many users are not used to viewing full-screen images. MMS videos may be formatted in a widescreen or portrait format, depending on the content. Widescreen mode is standard for television or movie clips, while portrait mode effectively uses space, and shows a larger video area, in message threads, making it easier to watch and add readable text.
MMS messages are sent to the destination mobile device's messaging app and displayed in a preview bubble. The preview bubble may cut off parts of the image or video content, and some apps may overlay controls. To maintain interest, position relevant content in the areas displayed in the preview bubble that is displayed prior to opening the message and displaying the content on a full screen.
In MMS messaging, it's crucial to consider image file size and image dimensions to improve deliverability rate. A smaller file size, such as 500Kb, can increase the rate of delivery. MMS image dimensions are typically measured by pixels, which are small dots or squares that affect resolution on a screen. It’s important to consider the trade-off between file size, quality, and delivery speed when sending multimedia content via MMS.
Our recommendations for file size depend on whether or not you plan to use transcoding:
If you are sending to a large subscriber base (that is, a base that is anywhere from hundreds of thousands to more than a million subscribers), we recommend uploaded file size of 300k or smaller. This will avoid slower batch delivery from the database.
The optimal image size across all devices has an aspect ratio of 9:16. We recommend 1080px by 1920px.
When an MMS image is delivered to a phone there are typically two ways the content is displayed. The content is displayed in the message conversation thread within a message bubble and then when the image bubble is tapped, the content is displayed in a full screen view. When when the image is displayed within a message bubble, there are portions of the image cut off from view. It's therefore important that any image be designed with the “content of interest” within a more restricted areas of the image so that it's readable from within the conversation view.