# Text messages by API: SMS, WhatsApp or email, which wins?

> SMS reaches every phone, WhatsApp carries media and read receipts, email carries documents. Compare them, then send on all three in one request.

Source: https://unlimitedmessaging.app/articles/text-messages

Text messages

# SMS, WhatsApp, email:  
_three channels, one API._

A text message to a customer can go out as an SMS, a WhatsApp message or an email. Each has its strengths: SMS reaches every phone, WhatsApp carries media and read receipts, email carries long content and files. With Unlimited Messaging, all three are channels of the same API, sent from your own number, SIM and mailbox.

[Start for free](https://app.unlimitedmessaging.app)[Get the Android app for SMS](https://unlimitedmessaging.app/channels/sms)

The context

## SMS, WhatsApp or email: which channel for a text message?

A text message used to mean one thing: an SMS of up to [160 characters per segment](https://www.twilio.com/docs/glossary/what-sms-character-limit) sent over the mobile network. Today the same message can reach your customer on three channels, each with its own reach, format and receipts.

SMS is the universal one. It reaches any mobile phone, iPhone or Android, with no app and no data connection, which makes it the safest channel for a short, urgent message. It is text only, and its receipts stop at "delivered", when the carrier reports it.

WhatsApp is where many people actually chat: more than 3 billion users, long messages, images and PDFs, and read receipts. Email carries the longest content, HTML layout and many attachments, and it is the channel people expect for documents, receipts and anything they will search for later.

Most businesses need more than one. With Unlimited Messaging, SMS (through our free Android app, from your own SIM), WhatsApp (from your linked account) and email (from your own mailbox) are three channels of the same POST /message endpoint. You choose per message, or send on all three in a single request, and every reply lands in the same inbox.

![Illustration: a comparison table where one column has every check, with the headline “SMS, RCS or WhatsApp?”.](https://unlimitedmessaging.app/_next/image?url=%2Fassets%2Farticles%2Fcovers%2Ftext-messages-en.png&w=3840&q=75)

Definition
Text message

A short written message sent to a person's phone or inbox. Today it travels as an SMS over the mobile network, as a message in an app like WhatsApp, or as an email.

Also called a text, an SMS or, on messaging apps, a chat message.

[Source: How long can a message be? - Twilio↗](https://www.twilio.com/docs/glossary/what-sms-character-limit)

Comparison

## SMS, WhatsApp and email side by side

The same text message, three channels. Here is what each one does well and where it stops, as sent through Unlimited Messaging.

__SMS, WhatsApp and email side by side__
| SMSyour Android phone | WhatsAppyour linked account                    | Emailyour mailbox                        |                                     |
| --------------------- | ---------------------------------------------- | ---------------------------------------- | ----------------------------------- |
| Reach                 | Any mobile phone, no app or data needed        | 3 billion+ users, needs the app and data | Anyone with an email address        |
| Sender                | Your own mobile number                         | Your own WhatsApp number                 | Your own email address              |
| Length                | 1,530 characters, up to 10 parts               | 1,600 characters per message             | Long text and HTML                  |
| Media                 | Text only, no MMS                              | One image, PDF or audio file             | Up to 20 attachments                |
| Receipts              | Delivered when the carrier reports it, no read | Delivered and read                       | No native read receipt              |
| Replies               | Inbox and webhook                              | Inbox and webhook                        | Inbox and webhook                   |
| Volume                | Human pace: carrier fair use, Android cap      | Paced sending from your account          | Your mail provider's sending limits |
| Best for              | Short urgent alerts, codes, people offline     | Conversations, reminders, media          | Documents, receipts, long content   |

SMS through the Unlimited Messaging Android app, WhatsApp through your linked account, email through your own mailbox. Limits as of November 2026.

Our approach

## One API, the channel is just a field

Validation, queueing, statuses and webhooks are the same for every channel. Only the transport changes: your phone, your WhatsApp account or your mailbox.

### One request, up to three channels

List WHATSAPP, SMS and EMAIL in channels: each one gets its own message, all linked by one dispatchId. Override the text per channel, for instance a shorter SMS.

1. 01  
### One inbox for every reply  
SMS, WhatsApp and email replies arrive in the same inbox and the same message.received webhook.
2. 02  
### Your own identities  
Your mobile number, your WhatsApp account, your email address. No rented sender, no shared domain.
3. 03  
### Everywhere you work  
Dashboard, REST API, TypeScript and Python SDKs, n8n, and the MCP server for Claude, ChatGPT and Cursor.

Channels per request: SMS, WhatsApp, email

3Channels per request: SMS, WhatsApp, email

Inbox and webhook for every reply

1Inbox and webhook for every reply

Characters max per SMS

1530Characters max per SMS

Attachments max per email

20Attachments max per email

The request

## The same message on SMS, WhatsApp and email at once

Give the recipient's phone and email in to, list the channels, and write the text once. Each channel can override it: here the SMS gets a shorter version, while WhatsApp and email get the full text.

POST /messageJSON

```
{
  "to": {
    "phone": "+33612345678",
    "email": "client@example.com"
  },
  "subject": "Your order #1042 has shipped",
  "text": "Hello, your order #1042 has shipped and will arrive Thursday. Track it from your account or reply to this message with any question.",
  "channels": [
    {
      "channel": "WHATSAPP"
    },
    {
      "channel": "SMS",
      "text": "Your order #1042 has shipped, arriving Thursday."
    },
    {
      "channel": "EMAIL"
    }
  ]
}
```

POST /message: three messages, one dispatchId, statuses per channel by webhook.

How it works

## Connect your channels, then send

1. 01  
### Create your account  
Sign up for free, then connect the channels you want: scan a QR code for WhatsApp, add your mailbox for email.
2. 02  
### Add SMS with your phone  
Install the free Android app and sign in. Each SIM becomes an SMS account, sending from your own number.
3. 03  
### Send on any channel  
Create an API key and call POST /message with one, two or three channels. Statuses and replies come back by webhook.

Key takeaway

### Pick the channel per message, keep one API.

SMS for short, urgent messages that must reach any phone; WhatsApp for conversations and media; email for documents and long content. With Unlimited Messaging they are three values of the same channels field, sent from your own number and mailbox, with every reply in one inbox.

FAQ

## Questions about SMS, WhatsApp and email

SMS when the message is short and must reach any phone, even without data. WhatsApp when you want media, read receipts and a conversation. Email for documents, receipts and long content. Many businesses use two or three for the same customer.

Yes. List up to three channels in POST /message with the recipient's phone and email in to. Each channel gets its own message, linked by one dispatchId, and you can override the text per channel.

A multi-channel request sends on every channel you list, at once. To send an SMS only when WhatsApp did not go through, listen to the status webhook of the WhatsApp message and send the SMS from your code when it fails.

Install the free Android app on a phone with a SIM and sign in. The SMS leave from that SIM, on your own carrier plan, with no per-message fee added by Unlimited Messaging. Keep it to your own traffic at a human pace: carriers forbid bulk sending on consumer plans, and Android asks for confirmation past about 30 SMS in a short window.

Yes. Any mobile phone receives the SMS. Only the sending phone, the gateway, must run Android 8.0 or newer.

Unlimited Messaging does not send RCS. The SMS channel sends standard SMS, which every phone receives, and WhatsApp covers rich messages with media and read receipts.

Sources

## Sources & references

To check the information in this article for yourself:

1. [01How long can a message be? SMS segments and character limits↗Twilio](https://www.twilio.com/docs/glossary/what-sms-character-limit)
2. [02Unlimited Messaging for Android - source code and releases↗GitHub](https://github.com/UnlimitedMessaging/unlimited-messaging-android)
3. [03WhatsApp - usage figures and statistics↗Statista](https://www.statista.com/topics/2018/whatsapp/)
4. [04WhatsApp - official site↗WhatsApp](https://www.whatsapp.com/)
5. [05Messaging Principles and Best Practices (May 2023)↗CTIA](https://api.ctia.org/wp-content/uploads/2023/05/230523-CTIA-Messaging-Principles-and-Best-Practices-FINAL.pdf)

![Ilian, senior software engineer](https://ilianazz.com/images/iliazz.png)

Written by

[Ilian](https://unlimitedmessaging.app/authors/ilian) · Senior Software Engineer

A senior software engineer, he founds and runs several tech companies. He builds products around messaging APIs, automation and AI integration, and shares here what he learns while building.

[View LinkedIn profile↗](https://www.linkedin.com/in/ilianAzz/)Updated November 7, 2026

![](https://unlimitedmessaging.app/assets/logos/whatsapp.svg)![](https://unlimitedmessaging.app/assets/logos/email.svg)![](https://unlimitedmessaging.app/assets/logos/sms.svg)

## Reach your customers on the channel they read.

Create your free account, connect WhatsApp, email and your Android phone, and send your first multi-channel message.

[Start for free→](https://app.unlimitedmessaging.app)

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