Short Messaging Service (SMS) is a long-standing, widely used way to communicate via text. respond.io sends and receives SMS through supported partners. After you create a partner account and provision a phone number, link it to respond.io and manage SMS conversations alongside your other messaging and calling Channels.
Supported SMS partners
respond.io supports these SMS partners:
To request a partner that isn't listed, submit it on the respond.io Feature Request board.
Channel capabilities
The capabilities of each supported SMS partner are listed below:
Message status availability
The message status availability for each SMS Channel is shown below.
SMS Channel | Sent | Delivered | Read | Failed |
|---|---|---|---|---|
Twilio | ✅ | ✅ | ❌ | ✅ |
MessageBird | ✅ | ✅ | ❌ | ✅ |
Vonage | ✅ | ✅ | ❌ | ✅ |
Telnyx | ✅ | ✅ | ❌ | ✅ |
Supported file types
The file types supported by each SMS Channel and the maximum file size for each are shown below.
SMS Channel | Image Size Limit (MB) | Audio Size Limit (MB) | Video Size Limit (MB) |
|---|---|---|---|
Twilio | 5 | 0.5 | 0.5 |
MessageBird | 1 | 1 | 1 |
Vonage | 2 | - | - |
Telnyx | 1 | 1 | 1 |
Metadata received by Channel
Each Channel provides a different set of Contact metadata to respond.io. The data available from each SMS Channel is shown below.
SMS Channel | Metadata Received by Channel |
|---|---|
Twilio | Phone number, City, State, Postal code, Country |
MessageBird | Phone number |
Vonage | Phone number |
Telnyx | Phone number |
Broadcasts
Supported SMS partner Channels have no restrictions on the content or number of messages a business can send in a broadcast. Broadcast messages are charged at the usual per-message rate.
- Learn how to send a simple broadcast.
- Learn how to troubleshoot a failed broadcast.
Rate limits
A rate limit is the number of API calls an app or user can make within a time period defined by the Channel. Learn more about the rate limits of each SMS Channel below.
