Standard MMS (aka, Multimedia Messaging Service) messages allow you to send images, slideshows, videos and audio clips as attachments. While this means you can do some creative things with your communications, there are some limitations to keep in mind.

The biggest limitation is that the recipient's phone may not support all multimedia files. So, while you may be able to send a short video, not all of your recipients may be able to view it.

Another thing to keep in mind is that some mobile carriers limit the file size of attachments being sent over their network. For example, Twilio limits messages that combine text and images to 5MB. If you try to send, say, an MMS message combining text and video, and the total size is greater than 5MB, Twilio will prevent the message from sending. Before sending out a large number of messages, it's a good idea to test your communications on various handsets using different file formats and sizes. See what works and what doesn't.

Twilio, Short Codes and MMS Messages

If you're using a Twilio short code, keep in mind that it doesn't automatically support MMS messages. You can add MMS capabilities for a one-time fee of $500. This is different than regular "long codes" (phone numbers) where MMS is usually automatically supported.

If you're not sure whether your account supports MMS messaging, check your Twilio Console. If you only see "Capabilities: SMS" and MMS is not listed, then it's likely you haven't purchased MMS for your short code.

See the setting up Twilio section for more information on configuring Twilio as your SMS provider.