The Difference Between SMS and MMS

Last updated at:


SMS marketing is the generic term most people use for marketing using text messages. Under the hood, there are actually two different formats that have distinct capabilities: SMS (short messaging services) and MMS (multimedia messaging services).

This article goes over the similarities and differences between these types of text messages and when to use them.

The Same: Consent

MMS and SMS are alike in an important way: consent

MMS marketing falls under the same consent guidelines as SMS. This means that you don’t need to re-gather consent from your current SMS subscribers for MMS marketing. If you already have someone’s permission for SMS marketing, you can start sending them MMS messages immediately.

Difference: Images/GIFs

The main difference between the two types is that MMS includes media besides just text (e.g., images), while SMS messages only include text.

In Klaviyo, all text messages start out as an SMS message. You are able to add an image or GIF during the content creation stage. Once an image is added, the message will automatically be converted to an MMS. You will see the image appear in the preview. Any message that does not include an image or GIF will remain as an SMS.

With MMS, you can send subscribers texts with branded images. You can show a product, your logo, an ad, a coupon, a graphic design, etc. Using an image or GIF can help your message stand out as well as make it feel more human.

You will not always want to include an image. Text-only messages are more direct and better for messages where you want to go straight to the point or the message is time-sensitive. For instance, with a transactional message, your goal is to keep the user updated about the status of their order/delivery, which doesn’t require an accompanying image or GIF. We recommend crafting your content first and then adding an image or GIF. This way, so you can make sure the media enhances your message. 

Difference: Number of Sends

Under Klaviyo's text message billing plans, the number of sends varies by message type and country. 

US  1 3
Canada 1 3
UK 3 N/A
Australia 3 N/A

This applies to both campaigns and flows. When picking a plan, remember to take into account how many MMS messages you plan to send. 

Difference: Character Limit

Another thing separating MMS and SMS is the character count. SMS messages can have up to 160 characters — 70 with an emoji. As for MMS messages, they can have 1600 characters. This allows you more space to explain your brand to recipients, include key details about events or product launches, or provide updates as you would in an email newsletter.

While MMS allows for longer messages, we recommend to still aim for around 160 characters. A best practice when creating content for text messages is to be as concise and personal as possible. SMS naturally has this limit, and are the best choice to quickly convey important information.


Note that the character count doesn't just include your letters and punctuation, emojis and symbols (e.g., ©) are also counted. 

Difference: Sending Numbers

You can send an SMS from any type of number: toll-free number, short code, or branded sender ID. 

MMS numbers are only available with:

  • Short/vanity codes
  • Toll-free numbers

When to Use SMS vs. MMS

Use MMS when sending an image or GIF will enhance the message, such as to make it more personal by showing more of your brand. MMS can also be useful for sending out information about a new product, giving you a stage to showcase it visually.

Do not include media for the sole purpose of writing a longer message — most customers do not want to read longer messages or see irrelevant visuals. In these cases, it is better to use an SMS and shorten the content to make it fit into one message.

SMS messages are also better when you want to convey information as quickly as possible. This can be the case if you’re having a flash sale or even for the first message in your welcome series.

Additional Resources

Was this article helpful?
40 out of 51 found this helpful