Top 5 Best SMS Gateway APIs to Send Text Messages

If your business or application depends on real-time communication, you need more than a messaging tool. You need an SMS gateway API you can trust.

Below, we’ll break down the best SMS gateway APIs on the market, what they do well, and who they’re best for.

Why use an SMS service provider to send text messages?

Businesses rely on SMS service providers for immediate, personal, and scalable communication. Text messages have open rates of up to 98%, with most texts read within minutes. This beats other communication channels by a long shot.

A robust SMS API enables you to:

• Send and receive text messages directly from your software

• Automate messages

• Trigger notifications

• Scale without babysitting your existing tech stack

• Utilize the full power for SMS gateways

What is an SMS gateway?

An SMS gateway enables a computer or application to send and receive Short Message Service (SMS) messages to and from the global telecommunications network. 

Instead of manually texting from your mobile device, an SMS gateway API connects your platform (CRM, POS, Helpdesk, etc.) to carrier networks, so you can automate and scale communications instantly.

The SMS gateway acts as a translator by adjusting the message’s format, so it can be transmitted over the network and reach its destination.

What should you consider when evaluating SMS gateways? 

The right choice can unlock a range of benefits for your application and communication strategy.

Businesses rely on SMS service providers to deliver immediate, personal, and scalable communication. With text messages achieving open rates of up to 98%—and most being read within minutes—SMS is a powerful tool for reaching your audience effectively.

When assessing SMS gateways, look for:

1. Pricing Structure

   • Is the pricing transparent and competitive?

   • Are there hidden fees for features like delivery reports or premium routing?

2. Routing Redundancy

   • Does the vendor offer reliable routing across the top 3 carriers in your region?

   • How do they handle failover to ensure message delivery during outages?

3. Support for Multiple Messaging Types and sending numbers

   • Can the vendor handle SMS, MMS, short codes, toll-free numbers (1-800), and 10DLC?

   • Are there limitations on the types of messages you can send?

4. API Documentation and Ease of Integration

   • Is the API documentation clear, detailed, and developer-friendly?

   • Are there SDKs or libraries available for your preferred programming languages?

5. Compliance and Regulatory Support

   • Does the vendor provide guidance on compliance with regulations like TCPA, GDPR, or carrier-specific rules?

   • Can you easily reach a compliance expert, or are you stuck with long wait times and automated responses?

6. Delivery Rates and Reporting

   • What are the vendor’s delivery success rates?

   • Do they provide detailed delivery reports and analytics to track performance?

7. Customer Support and Availability

   • Is support available 24/7?

   • Do they offer multiple support channels (chat, email, phone)?

8. Scalability and Performance

   • Can the platform handle high message volumes without delays?

   • Is it built to scale with your business as your messaging needs grow?

9. Global Reach and Localization

   • Does the vendor support international messaging?

   • Can they handle localization, such as time zones, languages, and regional compliance?

10. Reputation and Reliability

    • What do other businesses say about the vendor’s reliability and service?

    • Do they have a proven track record with businesses similar to yours?

11. Security and Data Privacy

    • How does the vendor protect sensitive customer data?

    • Are they compliant with security standards like SOC 2, ISO 27001, or similar?

12. Message Customization and Features

    • Do they offer features like personalization, templates, or dynamic content?

    • Can you easily manage opt-ins, opt-outs, and customer preferences?

While most SMS APIs offer similar core functionality, the real difference often comes down to compliance support and onboarding. Campaign registration, 10DLC approval, short codes, and toll-free requirements can easily become bottlenecks without the right provider.

The platforms below vary widely in how much guidance and support they offer beyond the API itself.

Top 5 SMS Service Providers with the Best SMS Gateway APIs

1. Esendex USA

Esendex USA is a powerful SMS gateway provider known for its enterprise-level delivery performance and developer tools. They focus heavily on security, scalability, and global carrier connectivity—making them a solid choice for teams that need stable, high-volume messaging.

SMS Gateway Provider Features

Esendex USA offers a feature-rich SMS gateway designed for businesses that need consistent delivery and robust infrastructure.

Key features include:

• High delivery rates

• Two-way messaging

• Number options including 10DLC, toll-free, and short codes

• Message personalization and templates

• Real-time reporting and delivery receipts

• Strong compliance and security standards (ISO 27001 certified)

Their platform is designed to support enterprise-grade traffic, making it suitable for organizations that need uptime guarantees and telecommunication-level reliability.

Esendex USA stands out for its hands-on support around SMS compliance, including campaign registration, 10DLC setup, short codes, and toll-free messaging. This level of guidance can significantly reduce delays and delivery issues.

SMS API Services

Esendex USA offers developer-friendly APIs for effective and scalable mobile messaging, with support for:

• SMS API

  • Bulk SMS

  • SMS Automations

  • Two-Way Chat

  • SMS 10 DLC

  • SMS Short Code

  • SMS Toll-Free

• MMS API

  • MMS 10 DLC

  • MMS Short Code

  • MMS Toll-free

• Voice API

  • Interactive Voice Response (IVR)

  • Answering Machine Detection

  • Text2Speech

  • Call Forwarding

Developers appreciate the clean documentation and sample code across major programming languages of Esendex USA’s APIs. This helps streamline the integration process into any existing tech stack.

Support Overview

Esendex USA differentiates itself through hands-on customer support. They provide direct guidance throughout onboarding, registration, and ongoing messaging operations to help businesses navigate the complexities of SMS compliance and campaign setup.

Unlike providers that rely primarily on ticket-based or email-only support unless customers upgrade to higher-priced tiers, Esendex USA emphasizes accessibility and responsiveness. Their support is designed to help teams launch campaigns faster, stay compliant as carrier rules evolve, and maintain reliable delivery as message volumes scale.

This proactive approach is valuable for businesses new to application-to-person (A2P) messaging or operating in industries with strict regulations.

Esendex’s support structure is a key advantage for organizations that need more than just an API. 

SMS Gateway Integrations

Esendex USA integrates with a wide range of platforms, including CRMs, helpdesks, and custom applications. They additionally offer Quick Start guides for popular frameworks:

• C#

• Java

• JavaScript

• PHP

• PHP with cURL

• Python

• Ruby

SMS Service Provider Reviews

Users praise Esendex USA for: 

• High deliverability rates

• Expert guidance on compliance and number selection

• Ease of API setup

• Strong adherence to compliance requirements

Some reviews also note that Esendex is more enterprise-focused, so smaller businesses without internal developer resources might not be the right fit. For small business needs, we recommend Text Request, which offers a flexible, no-code user experience and APIs for broader use cases.

SMS Service Provider Pricing

Costs vary based on message volume, number type (short codes, 10DLC, and toll-free numbers), and country. Most businesses will need to request a custom quote, regardless of size.

2. Twilio

Twilio is a leading cloud communications platform designed to support global omnichannel messaging across 180+ countries. They’re known for their comprehensive, developer-focused platform that offers flexibility and a suite of communication tools. 

Businesses expecting to scale quickly can benefit from Twilio’s platform, as well as anyone who needs full control over custom messaging workflows.

SMS Gateway Provider Features

Twilio’s platform offers SMS, MMS, voice, video, and more for a variety of number types. Their gateway supports both outbound and inbound SMS, making two-way messaging a breeze.

SMS API Services

Twilio’s core offerings are their Programmable Messaging API and Conversations API.

Their Programmable Messaging API enables you to send transactional messages through channels such as SMS, MMS, and WhatsApp. 

This API is ideal for:

• Triggering one-way or transactional bulk messages at scale

• Handling basic two-way replies (ex: “Reply YES to confirm”)

• Notifications, alerts, reminders, 2FA, etc.

Their Conversations API is built for full, long-lived two-way conversations across the same multiple communication channels. It’s designed for customer support, sales chats, and service teams to nurture 1:1 or group conversations with any relevant participants.

This API enables:

• Agents and customers to communicate within one threaded conversation

• Unified inbox across all communication channels

• Seamless media sharing

• Ability to view message delivery and read receipts

Twilio provides Software Development Kits (SDKs) for a range of popular programming languages, including: 

• Python

• Node.js

• PHP

• C# (.NET Framework and .NET Core)

• Java

• Go

• Ruby

SMS Gateway Integrations

Since Twilio is such a widely-used platform, it is often the backbone of custom integrations. 

Twilio commonly powers:

• CRMs

• Marketing platforms

• Internal tools and custom workflows

• Multi-channel communications

Support Overview

Twilio’s support model is primarily self-serve by default. Most customers are meant to rely on documentation, community forums, and ticket-based support, unless they upgrade to a higher tier that includes a support plan.

Many public reviews note that businesses managing SMS compliance such as 10DLC registration, are typically expected to handle the majority of the process independently.

This model works fine for engineer-led teams, but organizations that are seeking hands-on guidance during onboarding or campaign approval may find Twilio’s support more limited.

SMS Service Provider Reviews

Twilio generally receives positive feedback for things like:

• Its flexible and versatile capabilities

• Being developer friendly

• Seamless scalable communication

• Their pay-as-you-go pricing structure

Some users note the following drawbacks:

• Doesn’t offer much “out-of-the-box” ease, more of a DIY, technical setup—which can be a disadvantage and steep learning curve for non-technical users

• Might be overkill if you don’t need many features

• Costs add up quickly depending on volume, message type, sender number type, and country

• Lack of consistent customer support

• Experience is crowded by features that most projects don’t need, creating confusion

SMS Service Provider Pricing

Twilio’s pricing depends on the phone number type, the mobile carrier, and type of message your business wants to send. They offer a pay-as-you-go model, with SMS messages starting at $0.0083 in the United States. View their full pricing information here.

They also offer volume-based discounts which can help decrease per-message costs if your business plans to send messages at scale.

3. Vonage

Vonage is a major player in the SMS API space, offering a unified omnichannel communications platform built on Voice over Internet Protocol (VoIP). 

It’s a popular choice for businesses that need flexible APIs, competitive pricing, and solid carrier connectivity outside the United States. Vonage is especially ideal for engineering teams building communications directly into their apps.

SMS Gateway Provider Features

Vonage offers a powerful messaging gateway for both simple and high-volume use cases. It integrates with SMS, MMS, RCS, and popular social chat apps such as WhatsApp and Facebook Messenger.

Key features include:

• Global messaging coverage across 200+ countries and over 700 networks

• Automatic Unicode translation

• High-throughput SMS for transactional and operational messages

• And more

You can check out their full, all-inclusive features here.

SMS API Services

Vonage offers two main SMS-focused APIs:

• SMS API

  • Send and receive high volume of text messages globally using REST APIs

  • Send SMS with low latency and high delivery rates

  • Receive SMS via a local number

  • Scale your applications with familiar web technologies

  • Pay-as-you-go pricing structure

  • Auto-redact feature to protect privacy

• Messages API

  • Integrate with SMS, MMS, RCS, WhatsApp, Messenger, and Viber to communicate with customers on their preferred channel

  • Cost-effective chat experience

  • Easily develop and test

  • Instantly access valuable insights

  • JSON Web Token (JWT) authentication

Check out Vonage’s full list of SDKs and tools here.

SMS Gateway Integrations

Vonage integrates with a wide variety of platforms for most common enterprise and SaaS workflows, ranging from:

• CRM systems

• Communication hubs

• Verification and authentication tools

• E-commerce platforms

• Project Management and Productivity tools

Check out their full list of integrations here.

Support Overview

Vonage provides technical support through help center articles, live chat, email, phone, and ticket-based assistance. Many users report that their support responsiveness and depth can vary, depending on region, message volume, and contract level.

SMS Service Provider Reviews

Vonage users tend to like:

• Strong global delivery reliability and outreach

• Competitive international SMS pricing compared to other U.S.-focused providers

• Clean API design and easy onboarding

• Reliable customer support and developer documentation

• Affordable entry-level pricing with a clear ROI timeline

Their common drawbacks include:

• Issues with mobile app glitches

• Hidden surcharges, add-on fees, and early termination fees

• Outages that lead to SMS disruptions

• Limited SMS functionality for non-businesses

• Some advanced features not included in lower-cost plans and cost extra

• Unreliable customer support

SMS Service Provider Pricing

Vonage’s SMS API pricing varies depending on what type of number and carrier you are sending and receiving a message on. 

• Virtual Phone Number

  • Send a message: $0.00809 per message

  • Receive a message: $0.00649 per message

  • Rent a virtual phone number (SMS and Voice): $0.90 per month

• Toll-Free Number

  • Send a message: $0.00809 per message

  • Receive a message: $0.00649 per message

  • Rent a toll-free number (SMS and Voice): $1.75 per month

• Short Code Number

  • Send a message: $0.00809 per message

  • Receive a message: $0.00649 per message

  • Rent a short code number: 

    • Random: $1000 per month/billed quarterly

    • Vanity:  $1500 per month/billed quarterly

View their full SMS API pricing information here.

4. Sinch

Sinch (formerly known as CLX Communications) is a global Communications Platform-as-a-Service (CPaas) known for connecting business and customers through their enterprise-grade SMS APIs, anywhere on the planet. 

They’re especially popular among companies sending high-volume SMS traffic around the world, including one-time passwords (OTPs), alerts, and customer service messages.

SMS Gateway Provider Features

Sinch focuses on high-throughput messaging with strong global carrier connectivity. 

Their core SMS gateway features include:

• Global reach across 200+ countries with direct carrier relationships

• Best-in-class deliverability rates

• 1 and 2-way SMS notifications or conversational messaging

• Multiple sender ID options, choose from local numbers and short codes

• And more

Explore their full range of SMS features here.

SMS API Services

Sinch offers two main SMS-related APIs:

• SMS API

  • Send and receive SMS messages globally, through a single connection

  • Timely and cost-efficient communications

• Conversation API

  • Send and receive messages globally over SMS, RCS, WhatsApp, Viber Business, Facebook Messenger, and other popular communication channels from a unified interface

Their SDKs include Node.js, Java, .NET, PHP, and Python.

SMS Gateway Integrations

Sinch integrates with a number of popular enterprise systems and communication platforms, such as:

• CRM platforms

• Authentication and verification systems

• Marketing automation tools

• Helpdesk and customer support platforms

Sinch is ideal for companies who require strict compliance, reliable routing, or telecom-grade infrastructure.

View the full list of Sinch’s integrations here.

Support Overview

Sinch’s customer support experience has mixed feedback from users, with a notable number of Trustpilot users reporting challenges related to response times, issue resolution, and communication.

Many reviewers describe delays of days or weeks when attempting to get assistance, and some highlight difficulty reaching helpful support staff for troubleshooting or onboarding questions.

These sentiments are reflected in Sinch’s overall Trustpilot score of 1.5/5, where a significant number of users call out these frustrations.

SMS Service Provider Reviews

The general sentiment of Sinch is positive, with users praising things like:

• High delivery reliability internationally

• Strong performance for OTPs and authentication messages

• Direct carrier connections

• Scalable infrastructure for high-volume needs

• Omnichannel communications

Some drawbacks noted include: 

• Difficulty getting ahold of customer support and successfully resolving issues

• Pricing varies by country

• UX is geared more towards enterprise-level organizations

• Initial setup is complex and technical

SMS Service Provider Pricing

Sinch offers a pay-as-you-go pricing model, which gives businesses transparency, flexibility and competitiveness. However, most businesses need to contact Sinch directly for an exact quote or volume contract.

Their U.S. rates start at the following prices, but will vary depending on which carrier is involved and which country is selected:

10DLC

Send a message: $0.0078 per message

Receive a message: $0.0078 per message

Toll-Free Number

Send a message: $0.0078 per message

Receive a message: $0.0078 per message

Short Code Number

Send a message: $0.009 per message

Receive a message: $0.009 per message

View Sinch’s full pricing information here.

5. Bandwidth

Bandwidth is a global communications software company that owns its own telecom network in the United States. They provide voice, messaging, and emergency services through APIs for other businesses. 

Companies like Google, Microsoft, and Zoom use Bandwidth's platform to embed communications features into their own applications, such as in-app calling and messaging.

SMS Gateway Provider Features

Bandwidth’s key differentiator is that they own their own network. By cutting out intermediaries, this position strengthens their API offering—leading to optimized routing, higher reliability, and better cost control.

Key features include:

• High throughput for 10DLC, toll-free, and short code numbers

• “Bring your own number” capabilities

• Direct-to-carrier access for reliable messaging

• 10DLC, toll-free, and short code support

• Two-way SMS capabilities

• Real-time delivery receipts

• 100+ MPS capabilities

SMS API Services

Bandwidth offers several communication APIs across messaging, voice, and phone number provisioning. Their core SMS gateway APIs include the following services

• Short Codes: To send high-throughput messages

• 10DLC: Reach customers with a dedicated local number

• Toll-Free SMS: Deliver better digital experiences

• RCS: Support for Rich Communication Services

• Authentication API: For 2FA and verification

• Number Lookup API: For checking large batches of numbers to improve quality

• Global Text Messaging: Send and receive texts from around the world

Bandwidth provides SDKs for: 

• PHP 

• C#

• NodeJS 

• Java 

• Ruby 

• Python

SMS Gateway Integrations

Bandwidth integrates with a number of enterprise and SaaS systems, and is known for offering the most direct-to-carrier integrations in the world. 

Common integrations include tools across:

• UCaaS platforms and CCaaS platforms (Zoom, RingCentral, etc.)

• Conversational AI

• Trust services for authentication workflows and 2FA systems

• CRM and customer engagement software

• Contact center and customer service tools

Check out Bandwidth’s full list of integrations here. 

Support Overview

Bandwidth’s customer support is structured by tiers, starting with Signature, Premium, and Premium Plus. While basic support is included with all plans, users can opt to pay approximately $3,000 per month, and up to $7,500 per month. Paying extra for the premium plans grants access to faster response times, dedicated customer success management, and proactive support engagement.

Public reviews on sites such as Trustpilot and Software Advice suggest that this structure creates friction for customers who require more hands-on assistance without committing to higher-priced tiers. 

Users have reported dissatisfaction with customer support responsiveness and clarity, especially around navigating setup and compliance requirements.

SMS Service Provider Reviews

There are mixed reviews of Bandwidth, and the biggest criticism they face is being the foundation for most fraud and robocalls. 

Users praise Bandwidth for:

• Extremely reliable deliverability rates due to owning their own telecom network

• Transparency around compliance, 10DLC, and carrier regulations

• Good developer documentation and support

Some drawbacks include:

• Less global coverage compared to Twilio or Sinch

• Setup can be complicated and technical for teams who don’t have developers

• Cumbersome support/ticketing system

• Known for selling phone numbers to criminal scammers and spammers, and they take little to no security or accountability for this

SMS Service Provider Pricing

Bandwidth offers a pay-as-you-go pricing model with competitive rates in the U.S. The pricing for their messaging starts at the following rates below: 

U.S. 10DLC

SMS Outbound: $0.004 per message

MMS Outbound: $0.015 per message

U.S. Short Code

SMS Outbound: $0.008 per message

MMS Outbound: $0.020 per message

U.S. Toll-Free

SMS Outbound: $0.007 per message

MMS Outbound: $0.020 per message

Bandwidth is generally more cost-efficient than other competitors, especially for businesses sending primarily in the U.S.

Choosing the Best SMS API for Your Business

Choosing the right SMS API comes down to understanding what your business actually needs. Some providers are robust for global, high-volume delivery, and others focus on ease of use or developer flexibility.

The real differentiator is how much support each API can offer around compliance, campaign registration, and carrier requirements. Not all platforms provide the same level of guidance. Some prioritize flexibility and self-service, which can work well for developer-led teams. 

The best API is the one that aligns not just with your technical needs, but with the level of support your team needs to scale responsibly.

Start by clarifying your primary use case, whether it’s:

• Transactional alerts

• Two-way customer conversations

• 2FA verifications

• International messaging

And then consider factors like:

• Delivery reliability

• Pricing transparency

• API complexity

• Integrations with tools you already use

Twilio offers broad flexibility, Vonage and Sinch excel at global communications, Bandwidth delivers strong U.S. carrier control, and Esendex USA focuses on reliability, compliance, and dedicated support. 

Compare each provider’s strengths with your messaging needs to find the API that best aligns with your strategy and customer experience.