ChatGPT
Perplexity
Claude
Google AI
Text Messaging Formats: What They Are and Which to Use
“Text messaging formats” means two things, and people search for both. One is the channel a message travels on: SMS, MMS, WhatsApp, or RCS. The other is how the message itself is built: its length, encoding and attachments. Both affect whether your text arrives, how much it costs and whether anyone responds. This guide covers each.
The main text messaging formats
SMS is the oldest and most universal. It travels over the cellular network, needs no internet or app, and works on virtually any phone. It’s plain text only. That makes it a strong fit for appointment reminders, one-time codes, delivery alerts and urgent notices.
MMS extends SMS with images, GIFs, short video and audio. It also allows much longer text, commonly around 1,600 characters, though carrier limits vary. It costs more per message than SMS and works best in the US and Canada. Support is patchier elsewhere. Keep files small, since large ones may fail or get compressed. It’s a good fit for product shots, event invitations, and property listings.
WhatsApp Business messaging runs over the internet through Meta’s official business platform. It supports text, images, documents, video, buttons and lists, plus read receipts. There are two kinds of message. Template messages are pre-approved by Meta and start a conversation with someone who opted in. Free-form replies are allowed for 24 hours after the customer last messaged you. Meta charges for template messages by category and country, so check the current rate card. It suits customer support, order updates and markets where WhatsApp is the default app, like India, Brazil and much of Europe.
RCS is the upgrade to SMS inside the phone’s native messaging app. It supports high-resolution images, carousels, suggested replies, read receipts and verified business sender profiles. It needs a data connection. It works across Android and, since iOS 18 in 2024, on iPhones too, though business features and carrier support vary by country. Treat it as one to watch.
Push notifications and in-app messages aren’t text messages, but they sit alongside them. Push alerts need your app installed and notifications switched on. In-app messages show only while someone is using the app. They complement SMS and WhatsApp rather than replace them.
How a text message is actually built
This is where cost surprises come from.
- A standard SMS holds 160 characters when it only uses the basic GSM character set.
- Add an emoji, or characters outside that set (many non-Latin scripts count), and the whole message switches encoding, which drops the limit to 70 characters.
- A message longer than one segment is split and stitched back together, and each piece holds slightly less (153 characters, or 67 with the other encoding). You’re billed per segment.
So one emoji in a 150-character reminder can turn it into a three-segment, three-times-the-price message. That’s worth testing before a big send.
Format comparison
| SMS | MMS | RCS | ||
|---|---|---|---|---|
| Needs internet | ✗ | ✗ | ✔ | ✔ |
| Needs an app | ✗ | ✗ | ✔ | ✗ (native) |
| Images and video | ✗ | ✔ | ✔ | ✔ |
| Text length | 160 / 70 per segment | Long, carrier-dependent | Thousands of characters | Thousands of characters |
| Read receipts | ✗ | ✗ | ✔ | ✔ |
| Business approval | Registration in the US | Registration in the US | Meta templates | Verified sender |
Transactional vs. promotional texts
A transactional text is about something the customer did, like an order confirmation, a delivery notice, a verification code or a receipt. A promotional text sells something or announces an offer.
Don’t read “transactional” as “no consent needed.” In the US, automated texts to mobile numbers generally still require the person’s consent, and marketing texts need explicit written consent. Under GDPR and similar European rules, marketing messages need consent as well. Every text should honor opt-outs. Putting a promotion in a message labeled transactional is a real compliance risk. This isn’t legal advice, so check with counsel for your own setup.
Which format fits?
- Everyone, everywhere, no friction: SMS.
- Your audience lives in WhatsApp: WhatsApp Business messaging.
- Visual product promotions in the US: MMS.
- A mostly Android audience and a branded experience: RCS, as adoption grows.
- You work in Salesforce: pick a tool that runs inside it, so messages and consent live on the customer record.
How MessageBlink handles this
MessageBlink is a Salesforce-native app on the AppExchange for SMS and WhatsApp. It doesn’t support MMS. You can send and receive both channels from Salesforce records, trigger messages from Flow, store opt-ins and opt-outs on the contact, and report on delivery in standard Salesforce reports.