How is SMS Different from MMS? A Complete Guide to Text Messaging Technologies

SMS and MMS are among the best ways to communicate with customers. We have found the best response rates come from these methods. Despite the rise of instant messaging apps like WhatsApp, iMessage, and Telegram, SMS and MMS remain crucial communication tools, particularly in business messaging, emergency alerts, and two-factor authentication. In this article, we explain the difference between SMS and MMS, how they work, and the pros and cons of each.

What is SMS?

Short Message Service (SMS) is one of the most widely used communication technologies in the world, enabling simple, text-based messages to be sent between mobile devices. SMS is a communication protocol that allows you to send text messages from one phone to another. Text messages have an average open rate of 98%, making SMS one of the most effective communication channels available.

A Brief History of SMS

The first-ever SMS message was sent on December 3, 1992, by British engineer Neil Papworth, who transmitted "Merry Christmas" from a computer to a mobile phone on the Vodafone network. However, SMS as we know it took several years to become mainstream.

In the early 1990s, mobile networks were primarily designed for voice calls. Text messaging was an afterthought, introduced as part of GSM (Global System for Mobile Communications) networks in 1993. Early SMS adoption was slow because carriers initially restricted messaging to users on the same network. However, by the early 2000s, interoperability between networks was established, leading to a massive boom in SMS usage.

By 2010, SMS was at its peak, with trillions of messages sent annually. SMS is the most widely used text messaging method and virtually all mobile phone service providers in the country provide limitless texting as part of their packages. The last decade experienced rapid growth of the SMS messaging space, with six billion text messages sent daily in the U.S. While the rise of over-the-top (OTT) messaging apps has cut into its dominance, SMS remains a reliable, universal, and carrier-backed messaging solution.

How SMS Works: The Basics of the Protocol

SMS is a store-and-forward messaging system that allows mobile users to send short text messages, up to 160 characters, over cellular networks. It operates on the Signaling System No. 7 (SS7) protocol, originally designed for call setup and management in telephone networks.

Here's a high-level look at how SMS transmission works. First, a user types and sends a message from their phone. The message is then sent to the nearest Short Message Service Center (SMSC), which acts as an intermediary between sender and receiver. If the recipient's phone is turned off or out of coverage, the SMSC stores the message and attempts delivery later in a store-and-forward process. When the recipient is reachable, the SMSC forwards the message to their phone, and a delivery receipt can be sent back to the sender.

Key Technical Aspects of SMS

The 160-character limit is based on the GSM-7 encoding standard, which uses 7-bit characters. Longer messages are split into concatenated SMS, sent as multiple parts and reassembled on the recipient's device.

SMS supports optional delivery receipts, confirming whether a message has been successfully received. This delivery confirmation helps businesses track message success.

Unlike instant messaging apps, SMS operates over cellular networks, meaning it doesn't rely on Wi-Fi or mobile data. No internet connection is required to send or receive SMS messages.

Limitations of SMS

Despite its longevity and reliability, SMS has several technical and functional limitations.

SMS is limited to 160 characters per message when using GSM-7 encoding. If special characters are used, such as emojis or non-Latin scripts, the encoding switches to Unicode (UCS-2), reducing the message length to 70 characters per SMS. These message length constraints can be limiting for businesses trying to convey detailed information.

Standard SMS is text-only, lacking rich media support. If you want to send images, videos, or audio, you need Multimedia Messaging Service (MMS) or RCS (Rich Communication Services), both of which require carrier support.

Unlike modern messaging apps that use end-to-end encryption such as WhatsApp and Signal, SMS messages are unencrypted in transit, making them more susceptible to interception and man-in-the-middle attacks. This lack of end-to-end encryption is a security concern for sensitive communications.

SMS depends entirely on carrier networks, meaning messages may be delayed, filtered, or even blocked, particularly in high-volume A2P (Application-to-Person) messaging cases. This reliance on carrier networks can affect delivery reliability.

Since SMS does not have built-in spam detection, users are vulnerable to phishing attacks, known as smishing, where fraudsters impersonate banks, retailers, or government agencies to steal personal information. These spam and phishing risks are an ongoing challenge.

What is MMS?

Multimedia Messaging Service (MMS) is an extension of Short Message Service (SMS) that allows users to send and receive images, videos, audio, and rich media content via mobile networks. MMS is a communication protocol that allows you to send multimedia messages from one phone to another. While SMS is limited to text-only messages, MMS provides a richer, more engaging communication experience.

A Brief History of MMS

MMS was first introduced in 2002 as an enhancement to SMS, leveraging the same cellular infrastructure but with the added ability to send rich media. Unlike SMS, which is limited to 160 characters, MMS can carry images, video clips, audio files, and even formatted text, making it a significant upgrade in mobile messaging.

Initially, MMS adoption was slower than SMS due to higher costs for sending and receiving messages, carrier-specific restrictions and inconsistent implementations, and early mobile phones lacking strong media support.

However, as smartphone adoption increased and mobile networks improved, MMS became a widely used medium for brand marketing, customer engagement, and business communications. MMS messaging wasn't far behind SMS in growth. Available statistics show that MMS traffic across the country rose to 96 billion in just three years between 2010 and 2013.

How MMS Works: The Basics of the Protocol

Unlike SMS, which is transmitted over the SS7 signaling network, MMS relies on packet-switched networks, meaning it works more like email than traditional text messaging. Unlike SMS, MMS can also handle multimedia files up to 100 MB (MegaBytes), though in practice most carriers impose much smaller limits.

The step-by-step MMS transmission process works as follows. When a user sends an MMS, they compose a multimedia message with images, videos, audio, or formatted text. The message is packaged and sent to the user's carrier network. The message is then sent to the Multimedia Messaging Service Center (MMSC), where the carrier routes the message through an MMSC, which stores and processes the media.

During the message delivery process, if the recipient's phone supports MMS, the message is delivered directly. If not, the recipient receives an SMS with a link to view the media via a web browser. Finally, the recipient's phone downloads the multimedia content from the carrier's servers, completing the transmission.

Key Technical Aspects of MMS

Unlike SMS's 160-character limit, MMS can include thousands of characters in formatted text, providing an increased character limit for more detailed messaging.

MMS supports rich media, allowing for images, videos, GIFs, audio files, and slideshows. This capability makes MMS ideal for visual marketing and engagement.

While MMS is delivered over mobile networks, it does not require mobile data or Wi-Fi to function. No internet is required, making MMS accessible even in areas with limited data coverage.

Limitations of MMS

Despite its advantages, MMS has several technical and functional limitations that have prevented it from fully replacing SMS.

MMS messages are limited in size depending on carrier policies. Typical MMS size limits are 300 KB to 600 KB per message on most carriers. Some networks allow up to 1 MB, but this is uncommon. Larger media files are compressed, often reducing quality. These file size restrictions can impact the quality of media shared.

Not all mobile carriers or devices handle MMS in the same way. Some older or low-end phones may not properly receive MMS, instead displaying a link to view the media in a browser. This inconsistent carrier and device support can affect message delivery.

MMS is often more expensive than SMS. While SMS costs fractions of a cent per message, MMS pricing is significantly higher, particularly for bulk messaging. These higher costs can impact budget considerations for businesses.

Because MMS messages contain larger files, they take longer to process and deliver than SMS. This makes real-time messaging less efficient compared to standard text messages, resulting in slower delivery times.

Like SMS, MMS lacks encryption, making it less secure than modern messaging apps like WhatsApp and Signal, which offer end-to-end encryption. This lack of end-to-end encryption presents security concerns.

SMS vs. MMS: What Are the Differences and Similarities?

Both short message service (SMS) and multimedia messaging service (MMS) allow simple communication with friends, family, coworkers, and customers. They're both associated with text messages, but MMS can also include images, audio recordings, videos, weblinks, contact information like address and phone number, and other rich media content.

The main advantage of these messaging services over other forms like iMessage or WhatsApp is that nearly every cell phone has an SMS plan, and you don't need internet access to send and receive messages. This universal compatibility makes SMS and MMS reliable choices for business communications.

There are also some similarities between SMS and MMS. Both allow you to send text messages to multiple people at once, making them effective for broadcast messaging and group communications.

How Do SMS and MMS Compare to OTT Applications?

OTT, or over-the-top, applications are messaging services that use the internet to send messages. The most popular OTT applications are WhatsApp, Facebook Messenger, and iMessage. These applications offer many features such as sending photos, videos, and other types of files.

The main advantage of OTT applications over SMS and MMS is that they offer more features. OTT applications can send multimedia files up to 4 GB in size, much larger than the typical 300 KB to 600 KB limit for MMS. They also provide end-to-end encryption, read receipts, typing indicators, and other modern messaging features.

The main disadvantage of OTT applications is that they require internet or cellular data access. If you're not connected to the internet, you can't send or receive messages using an OTT application. This can be a problem if you're traveling or in an area with limited internet access. Additionally, both the sender and recipient must have the same app installed, which limits universal reach.

Why SMS and MMS Are Still Relevant Today

Despite their limitations, SMS and MMS continue to be widely used in key areas.

Business Communications

Many companies use SMS and MMS for customer notifications, appointment reminders, promotional messages, and service updates. The high open rates and universal compatibility make these channels invaluable for customer engagement.

Two-Factor Authentication (2FA)

SMS-based OTP (One-Time Passwords) remain a common security measure for login verification. Both SMS and MMS can be used for more visually engaging authentication codes or security messages.

Emergency Alerts

Governments and organizations rely on SMS to send critical weather warnings, disaster alerts, and public safety notices. The reliability and universal reach of SMS make it essential for emergency communications.

Marketing and Customer Engagement

Brands send rich media ads, GIFs, and product images directly to customers' phones via MMS. Companies use these channels for personalized messages, product previews, order confirmations, and shipping updates with images.

Global Reach

Unlike OTT messaging apps, which require an internet connection and app installation, SMS works on any phone, anywhere in the world. This universal compatibility ensures messages reach their intended recipients.

Healthcare and Other Industries

Doctors and clinics share appointment details, test results, or prescription instructions via MMS. Retail and e-commerce businesses benefit from visual product displays and order updates.

The Future of SMS and MMS

While SMS and MMS are not going away anytime soon, newer technologies like RCS (Rich Communication Services) are being positioned as their successor.

RCS, often referred to as "SMS 2.0" or "SMS/MMS 2.0," supports rich media, read receipts, typing indicators, and encryption features similar to iMessage and WhatsApp. Unlike MMS, which has file size restrictions and carrier dependencies, RCS operates more like an instant messaging service.

However, RCS adoption faces challenges. Apple's support for RCS has been limited historically, making cross-platform messaging difficult. Carrier adoption is inconsistent, with some networks lagging in support, and its adoption has been slow due to carrier inconsistencies and lack of universal implementation.

In the meantime, SMS and MMS continue to evolve through better security measures such as Verified SMS and STIR/SHAKEN for call authentication and improved filtering to reduce spam and fraud.

Signalmash SMS/MMS Solutions

Customers are demanding instant contact and communications with organizations. In a Global Mobile Messaging Consumer Report, nine out of ten people want to use messaging to interact with businesses. Yet only 48% of businesses are equipped to connect with customers through SMS/MMS.

Our Signalmash platform helps organizations deliver their messages quickly and maintain better engagement with contacts. Our messaging solutions leverage state-of-the-art SMS and MMS technologies to rapidly and reliably deliver enterprise messages to their intended recipients.

We provide a developer-friendly platform to let you quickly integrate communications features like SMS and MMS into your existing app via an API. We are a CPaaS platform and deliver millions of text messages each week for businesses in SaaS, education, property management, healthcare, staffing and human resources, utility and various other industries. We navigate the complexity of the worldwide network to provide industry-leading message delivery, allowing you to get the most out of your leads.

Our solution includes several options for automated response handling and new channels, such as two-factor authentication, push notifications and schedule reminders so your service and product can adapt to and change with the demands of your audience.

Conclusion

SMS may be an aging technology, but it remains a vital part of modern communication, thanks to its reliability, universal compatibility, and carrier support. Whether it's used for personal messaging, business communications, or security authentication, SMS continues to play a crucial role in the global messaging ecosystem.

MMS may not be the most advanced messaging format, but it remains one of the few universal, carrier-supported options for rich media messaging. With its ability to send images, videos, and formatted text without requiring an internet connection, MMS is still a valuable tool for businesses, marketers, and service providers.

For now, both SMS and MMS continue to be viable solutions for businesses looking for universally compatible messaging options that work across all devices and networks.

Reach out to us today and find out how our SMS/MMS capabilities can make a difference for your enterprise. Ask us how you can cut your Twilio or CPaaS bill up to 50%!

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