Full disclosure: this guide is published by SimplyRCS, so we are on the list. Every rate is the vendor's own published figure or is marked as quoted, and each entry links to a line-by-line comparison that also says where that vendor is the better call.
The eight, at a glance:
- SimplyRCS, one API for RCS, SMS and MMS with automatic per-recipient fallback, published rates, verification filed for you.
- Twilio, the widest API surface and ecosystem; published per-message rates with fees on top.
- Telnyx, the lowest published rates and free 24/7 engineering support, on its own network.
- Plivo, pay-as-you-go with an open rate card and proper RCS feature support.
- Vonage, a global Messages API beside voice and video; RCS rates not published.
- Sinch, global carrier reach under one contract; quoted.
- Infobip, omnichannel across sixty-plus countries; quoted, with per-interaction fees.
- Bandwidth, its own US network, sold on contract to enterprises and wholesalers.
What an SMS API needs to do now that RCS exists
Sending a text is the easy part of every API on this list. The differences are in the four things around it. Fallback: whether one call sends RCS where it can and SMS where it must, and reports which each recipient got, or whether you build that logic. Registration: who files the 10DLC brand and campaign and the RCS agent, you or the provider. Events: whether delivery, read and tap events arrive as one normalised webhook stream or three. Pricing lines: what sits beside the per-message rate, from carrier fees to number rentals to failed-message charges. The RCS API overview explains how every provider here wraps Google's RBM API underneath.
The providers, compared
1. SimplyRCS: best for one API with fallback and filing included
The REST API is the same interface the app uses: send a message and the platform checks each recipient, delivers RCS or falls back to SMS or MMS, and returns delivery, read and tap events through one set of webhooks. Rates are published, $0.0039 per SMS or RCS text and $0.0150 per MMS or RCS media, with carrier fees at cost and $250 a month per verified agent; brand, 10DLC and agent registration are filed for you. Honest limits: US carriers only. Developer overview.
2. Twilio: best for the widest API surface
Programmable Messaging covers SMS, MMS, RCS and WhatsApp with mature SDKs and documentation. SMS is about $0.0083, basic RCS the same, rich media about $0.0220, with carrier fees, number rentals, registry fees and a $0.001 failed-message charge on top; verification is self-serve. SimplyRCS vs Twilio.
3. Telnyx: best for the lowest published rates
Carrier-owned, developer-first, free 24/7 in-house engineering support. SMS at $0.004 per part on 10DLC, RCS at $0.0065 per segment for rich text and $0.016 for rich media, no platform fee, a capabilities-check API for fallback decisions; you build the tooling. SimplyRCS vs Telnyx.
4. Plivo: best for pay-as-you-go with an open rate card
$0.0077 per segment for SMS and RCS rich text, $0.0180 rich media, plans from about $25 a month; rich cards, carousels, suggested replies and verified senders supported; no app or inbox. SimplyRCS vs Plivo.
5. Vonage: best beside Vonage voice and video
A global omnichannel Messages API; US SMS list rate around $0.0068 plus carrier fees; RCS documented as a three-class model with the US rates not published; self-serve verification. SimplyRCS vs Vonage.
6. Sinch: best for global carrier reach
One of the largest carrier networks in the world, RCS through the Conversation API, US RCS rates quoted, six to twelve weeks to first send per Sinch's own guidance. SimplyRCS vs Sinch.
7. Infobip: best for omnichannel across sixty-plus countries
RCS as one channel in a broad omnichannel API with direct operator connections in more than sixty countries; quote-priced, with a per-interaction processing fee reported on Moments. SimplyRCS vs Infobip.
8. Bandwidth: best for wholesale capacity on contract
Owns its nationwide US network and sells contract-first to enterprises and CPaaS resellers; publishes its fee structure but not the rates. SimplyRCS vs Bandwidth.
Comparison table
| Provider | SMS rate (US 10DLC) | RCS rates | Fallback | Verification |
|---|---|---|---|---|
| SimplyRCS | $0.0039 per message | $0.0039 text or card, $0.0150 media | Automatic, per recipient, reported per channel | Filed for you |
| Twilio | ~$0.0083 plus fees | ~$0.0083 basic, ~$0.0220 rich media | Via Messaging Service | Self-serve |
| Telnyx | $0.004 per part | $0.0065 per segment, $0.016 media | Capabilities-check API; you route | Self-serve |
| Plivo | $0.0077 per segment | $0.0077 per segment, $0.0180 media | You build | Self-serve |
| Vonage | ~$0.0068 list | Not published | You build | Self-serve |
| Sinch | Quoted | Quoted | Conversation API | Assisted |
| Infobip | Quoted | Quoted | Omnichannel API | Enterprise |
| Bandwidth | Contract | Contract | You build | Contracted |
Rates verified September 2026 against each vendor's published pricing or the linked comparison page; carrier surcharges apply on top at every provider.
How to choose
- A US programme, engineering wants one call and no registration project: SimplyRCS.
- Lowest published rate, engineering will build the rest: Telnyx or Plivo.
- The broadest ecosystem, regardless of what is included: Twilio.
- Many countries under one contract: Sinch or Infobip; Vonage if you are already inside it.
- Wholesale capacity: Bandwidth.
Frequently asked questions
What is the best SMS API provider?
For a US programme that wants one API for SMS and RCS with fallback handled and registration filed, SimplyRCS. For the lowest published rate with engineering building the tooling, Telnyx. For the widest ecosystem, Twilio. For many countries under one contract, Sinch or Infobip. There is no single best; the rate is one line of the comparison and what surrounds the API is the rest.
Which SMS API providers publish their pricing?
SimplyRCS ($0.0039 per SMS), Telnyx ($0.004 per part), Plivo ($0.0077 per segment) and Twilio (about $0.0083) publish US SMS rates; the same four publish RCS rates. Vonage publishes an SMS list rate but not RCS. Sinch, Infobip and Bandwidth price by quote or contract.
Do SMS APIs send RCS too?
All eight here do, but not in the same way. Some send RCS through the same call with fallback handled for you; others expose RCS as a separate channel and leave the fallback logic, the agent registration and the per-channel reporting to your integration. The difference is most of the engineering effort in an RCS programme.
How much does an SMS API cost?
Per message, from $0.0039 (SimplyRCS) and $0.004 (Telnyx) to about $0.0083 (Twilio) on a US 10DLC number, before carrier surcharges, which every provider passes through and some mark up. Number rentals, registry fees, failed-message charges and platform or support fees vary by provider and are the lines to check beyond the rate.