Sending SMS Messages

Sending SMS Messages with the OneSignal SMS Composer.

This page explains how to send SMS & MMS from the OneSignal Dashboard. Other options for sending messages include:

API Create NotificationUse our server-side API to send push, email and sms. We also provide Server Side SDK's for faster implementation.
JourneysOrchestrate push notifications, emails, in-app messages, and SMS through a visual builder with no code required.
IntegratelySend push notifications, email or SMS using Integrately or push notifications using Zapier.

Sending SMS Notifications from Dashboard

Navigate to Messages > New Message > New SMS


Image, showing where button is to create a new SMS

Optional: Input a Message Name for internal recognition of the message. See Message Name for more details.

Step 1. Audience

The Segments of devices in which you wish to include and exclude from receiving this message.



Segments can be Edited

Any selected segments can be edited and new segments can be created on the fly.

Step 2. Message

Set From Number

Select the phone number that will send the SMS message. We will auto-fetch the list of phone numbers registered with your Twilio account.

Note: If you have registered your own phone number on Twilio and want to use that number to send SMS then Twilio only allows sending domestic messages.


Create Message

Enter the SMS text here. A normal text message character count is limited to 160 characters for GSM-7 encoding and 70 characters for UCS-2 encoding.


SMS Costs

Twilio (and carriers) charges for the number of segments that a single message gets split into. If the character count is greater than the above-stated counts, then carriers will split the message into multiple segments. A single "message" will then be charged based on the number of segments. See how SMS character count is calculated here.

OneSignal's form will help estimate the number of characters used so you can measure the costs of your SMS.


OneSignal supports emojis in your SMS content. However, emoji rendering and character count are not standard so please test the SMS before sending it to understand how they render and if they impact the character limit.


You can send URLs within SMS messages. Shortening those URLs is also recommended. However, using public URL shorteners like TinyUrl or Bitly have been forbidden by many carriers due to bad actors. If you want to send shortened URLs, it is recommended to use your own dedicated short domain. More details.


OneSignal supports tags to personalize your text messages. For example, you can personalize SMS to each user with the {{ first_name | default: ‘default_value’ }} tag if you have added that previously. See Message Personalization for more details.

Note: Tag substitution in the message content can result in the SMS exceeding the character count limit. This can result in additional cost to you. Please test your SMS content before sending it.


Multimedia Message (MMS). You can add up to 10 media URLs in an SMS with a total message size of less than 5MB. The following media types are fully supported.

  • image/jpeg
  • image/gif
  • image/png

Twilio also accepts other media formats, but the content will not be modified for device compatibility.

Note: Twilio only supports MMS in the US and Canada.

Test SMS before sending

To test how your SMS content looks on different devices or how the message is segmented, please use the "Send a Test SMS" functionality above the message preview. Simply enter your test phone number to receive the SMS content.


Tag Substitution Limitation

Tag Substitution will not work with Send Test Message. You will need to setup a segment to send to yourself to test or use the API.


Key considerations

Test messages will be charged against your Twilio account balance.

For Twilio trial accounts, recipient phone numbers need to be registered on Twilio before they can receive SMS.

Step 3. Delivery Schedule

SMS & MMS can be sent immediately or scheduled up to 30 days in advance.


When ready, click Review & Send to review your message and Send Message.

If you need more time or help, you can Save as Draft to come back to it later. A Draft is not reusable like a Template.