10 Best SMS APIs for 2025

SMS stands for ‘short messaging service.’ Any text message that’s 160 characters or less counts as an SMS.

An API (Application Programming Interface) is a set of rules that dictates how two applications should pass information between each other. 

Put them together, and you have an SMS API: a tool that allows developers to add SMS functionality to web applications without needing to write code from scratch.

You can use SMS APIs to automate confirmation texts, send follow-up messages, ask customers for reviews, and more. 

But not all SMS API providers are created alike, as you’ll see in the section below.

• “I started with just the basic features, and as my business grew, I started unlocking the power of OpenPhone by upgrading to the premium version. All of my office staff love using OpenPhone because it makes their jobs so much easier. … OpenPhone integrates with other applications, which can really boost its SMS capabilities. Don’t waste time with another solution.” — Trustpilot
• “What I love about OpenPhone is how easy it makes communication in property management. I use it mainly for chatting with tenants, homeowners, and vendors, and it just streamlines everything. The texting feature is a lifesaver for quick back-and-forths about maintenance requests or tenant questions.” — G2
• “This software allowed me to merge my VoIP number along with my texting package, all at the same price I was currently paying just for texting. It also allows utilization of my cell phone for work calls as well.” — GetApp

• “Setup is super complicated with seemingly multiple areas to set up the same things, but they’re different features. It took us weeks to actually set up properly to start sending texts out.” — GetApp
• “One of our senior developers had to spend 3 work days to find out that Twilio on IE1 was broken. [Zero] documentation, no explanation on the APIs that are unchanged since 2010, so they had plenty of time to document them, poor isolation (even not existent) between regions, so screw GDPR, gives the appearance of legitimacy. … Overall, expected way better. [Got] poor results.” — Trustpilot

Twilio’s API pricing depends on the type of number and text message you’re sending. In USD, it costs $0.0079 per outbound/inbound SMS whether you’re using short codes, toll-free numbers, or ten-digit long codes (10DLC).

Keep in mind this doesn’t include other costs, such as carrier fees and failed messaging processing fees. You’ll also pay monthly for a texting phone number, which could be several thousand dollars if you opt for a short code.

• “There is room for improvement in the API call logs to make them more informative. We also experienced occasional speed issues. It’s challenging to determine whether these speed issues are solely dependent on Plivo, as the delivery of text/calls also relies on the carriers used by our customers.” — G2
• “We chose Plivo for its competitive pricing. Soon enough we paid for our mistake. SMS failures one after another… Outages, failures, and timeouts are quite common. Even when the “system” is up and running, our end users complain a lot about not receiving the SMS.” — Trustpilot

Plivo starts at $0.0055 per inbound and outbound message through long code and short code numbers. Toll-free numbers are slightly more expensive at $0.0065 per inbound/outbound text.

Keep in mind that this doesn’t include additional carrier surcharge fees, which range from $0.0025 to $0.0050 per inbound/outbound text. There are also add-on costs to consider, including message queuing and the Powerpack.

• “…While the service is reliable, their support team’s response time is poor. If we open a support ticket, rarely do we hear back in less than 12 hours. Normally it’s 24 hours at least, and their responses are cryptic and seldom resolve the issue immediately. It can be another 12-24 hour response time while they research the issue.” — G2
• “Our business subscription started with a very friendly sales representative who was helpful and offered a good price. However, it took 4 months to get SMS going, our service was interrupted at least twice a month, and even once our SMS was approved, they then had a massive disruption again that took a month to fix.”  — Trustpilot

• Inbound messages: $0.00590 per inbound message
• Outbound messages: $0.00735 per message

For more on Vonage pricing, read our full cost breakdown guide.

• “They have a great API, which makes it easy to automate any process. The documentation can be a little unclear. However, their flexible SDKs make up for it.” — GetApp
• “Robust API for custom integrations. Initial setup may require some technical expertise. Pricing could be a concern for smaller teams.” — G2

Bird charges the following per-message rates for outbound messages in the US: 

• Local numbers: $0.00331 per SMS
• Short codes: $0.0039 per SMS
• Toll-free: $0.00464 per SMS

• “I’d give it 5 stars if we could send MMS without requiring a photo, filter out history, [and] implement RCS.” — Trustpilot
• “It’s useful, but it can get a little costly. It allows me to send “push notifications” of sorts from a web app. It charges per text message, but only allows like 160 characters per text, and [it] charged me to send two or three texts when I thought it was just one!” — G2

• Under 5,000 SMS per month: $0.0233 per text
• 5,000 SMS or more: $0.0167 per text
• Outbound MMS: $0.0330 per text

• “The ST team responds quickly to questions, and the interface is very user-friendly. [There are] some limits using the API integration, and some thresholds we were unaware of with certain message types or number of messages sent. This was to prevent SPAM texting, but should be disclosed to users up front…” — GetApp
• “I’ve used this app for over a year for my business to text groups and customers details for tours they’ve booked. While it can work well, I’ve run into multiple issues getting quick and efficient support when messages aren’t being pushed through. … My messages are often time-sensitive, and to keep a message in ‘monitoring’ for over 30 minutes is detrimental to my business model, as well as frustrating when 15 minutes is listed as the max time messages should be held.” — Trustpilot

SimpleTexting starts at $39 per month (+$4 one-time US carrier registration) for 500 message credits and one local number. Additional credits are billed at 5.5¢ each, although you can upgrade your plan for additional bandwidth.

• “Bandwidth offers functionality for ordering phone numbers and enables routing SMS/MMS text messages, which are both good benefits. The software features are chaotically split so that ordering telephone numbers uses an entirely different API and standard than sending text messages. The application platform must have credentials to access the dashboard API.” — GetApp
• “Their API isn’t as easy to work with as Twilio’s, but their pricing is much better.” — G2

Inbound messages with Bandwidth’s SMS API are 100% free (apart from carrier fees).

Here are its prices for outbound SMS:

• US 10DLC numbers: $0.004 per message
• US short code numbers: $0.008 per message
• US toll-free numbers: $0.007 per message
• Global 2-Way: $0.040 per message
• Global Alphanumeric: $0.040 per message

• “Telnyx has been a solid choice for our business communication needs. I wish there was more documentation or step-by-step guidance for certain features.” — G2
• “With Telnyx, we were able to eliminate the traditional complexity of international number provisioning. [It does] require programming experience for the Programmable APIs for seamless voice/SMS embedding.” — GetApp

• Inbound and outbound SMS with local numbers: $0.004 per message segment (plus carrier fees)
• Inbound and outbound SMS with toll-free numbers: $0.0055 per message segment (plus carrier fee)
• Inbound and outbound SMS with short code numbers: $0.007 per message segment (plus carrier fee)

• “Provides an SMS gateway API to interact with websites and incorporate text messaging capabilities into daily activities. Textmagic’s customer service continues to be poor. Contact management could be simplified.” — G2
• “I like Textmagic, however, when sending bulk text messages, not all recipients get the messages. Also, I don’t like it that when sending a Spanish text, I get charged more for using special characters.” — Trustpilot 
• “Often have messages that don’t get delivered, and there’s no way to know or check. Makes it very difficult to use for business communications. Support had no interest in helping, just gave me unrealistic requirements to be able to even look into it.”  — Capterra

You need to purchase a paid plan to access SMS API through Textmagic. You have three options:

• Essential: $24.50 per month for 500 SMS, unlimited users, and inbound messages ($0.02 per inbound text)
• Professional 2K: $80 per month for 2,000 SMS, free inbound texts, and one local or toll-free number
• Professional 10K: $100 per month for 10,000 SMS, texting numbers from CPaaS, and integrations with Twilio, Vonage, or Sinch