Best Voice Calling API & SDK Providers with a Free Trial of 2025

Video calling API for apps Sendbird's voice and video APIs, built for massive scale, make high-quality calls easy to integrate into your web and mobile apps.

Use the language you already love to prototype ideas quickly, develop production-ready communications applications, and run serverless applications on one API-powered platform. Twilio is a single fully-programmable platform with flexible APIs for any channel, built-in intelligence, and global infrastructure to support you at scale. Quickly integrate powerful APIs to start building solutions for SMS and WhatsApp messaging, voice, video, and email. Browse documentation and SDKs in multiple coding languages, including Ruby, Python, PHP, Node.js, java, and C#, or jumpstart your first project with our open source code templates to quickly build production-ready communications apps. Consult our community of over 9 million developers for guidance and inspiration on your next project. Sign up and start building today.

Plivo Communications Platform is a Cloud API Platform as well as a Global Carrier Services Provider. It offers high-quality cloud communications at an affordable price. Plivo Communications Platform allows users to make phone and SMS calls to all countries. It also allows them to buy local numbers in 55 countries. Plivo Communications Platform offers free tech support that is available 24/7. Experts are happy to help customers with any issues.

ClickSend offers SMS, MMS, Voice, Online Mail, Email and Fax software for businesses. Our communications and messaging tools are simple to use, automate and integrate. That’s why they’re used by some of the most trusted brands, organisations and developers globally. Built for all, you can access ClickSend via our Dashboard, mobile app, flexible API or 900+ integrations. Plus, ClickSend offers helpful 24/7 support, and lightning fast delivery via a secure and reliable platform. From SMS marketing and alerts to bulk mailouts sent from your browser, join over 90,000+ businesses sending communications around the world. Our 100% uptime guarantee and lightning fast direct routes provide reliable messaging, no matter the channel. From small businesses to enterprise, ClickSend powers billions of messages around the world with 232+ direct carrier connections. Plus, ClickSend is always pay-as-you-go. That’s why ClickSend is business communications, solved.

MirrorFly is a custom CPaaS provider powering businesses and enterprises with real-time communication, such as instant messaging, voice calls, and video conferencing through Chat APIs and SDKs. Regardless of the use case, tech stack, and devices, MirrorFly supports brands across the world to build their own chat platform with complete customization and zero limitations. MirrorFly’s Key CPaaS Benefits: ✅ Host on Your Own Server ✅Unlimited Customization ✅ Complete Data in Your Hand ✅ 1000+ Features ✅ Custom Security (Gmail, Phone, BioMetric, etc) ✅ Upload Enlarged Files (3+ GB) ✅ Mulit-tenant Server ✅ Scale 1+ Billion Concurrent Users ✅ Free Migration & Integration ✅ Hire Your Own Dedicated Team

EnableX makes it easy to integrate real-time communications into applications or workflows. It was designed and developed for Service Providers and Systems Integrators. It provides a robust, scalable, secure communications platform without the complexity and maintenance of maintaining the network infrastructure. Developers can quickly customise and embed all of the communication functions, such as voice, video, and SMS, into existing applications, workflows, and systems by simply using EnableX's extensive sets of programmable SDKs and APIs. Businesses can communicate with customers worldwide using the Virtual Number services, as well as advanced features like AI and NLP.

AVOXI Genius is a cloud-based, cost-effective, and simple-to-use call center software. You can easily manage your business communications using a web-based contact centre. AVOXI Genius integrates your contact center solution with voice service. Virtual phone numbers are available for activation in 170+ countries. AVOXI Genius is the best-selling solution in the world, with plans starting at $19.99 per person. Enjoy 2 months of free service for a limited time.

Engage customers like never before, on any channel. CPaaS, APIs for SMS Voice, Video, and Verification. In seconds or less, reach every mobile phone in the world. Engaging customers in the right way can help increase your webshop orders by more than just doubling. We're experts in this field. A major telco company was able to do exactly that using an online chatbot. We assisted a major automative company to re-engage and convert end of funnel prospects who were not responding to emails. The personalized Rich SMS campaign's results speak for themselves. Are your customers missing important appointments? SMS reminders can help you and your customers increase revenue. Trusted by developers all over the globe. With just a few lines code, you can build confidence and boost your business. Connect with your customers and add value every step of their journey.

CometChat is a live chat platform that allows users to collaborate and connect with customers. Developed with API and Chat SDK, CometChat can be deployed on-premise and cloud. The solution enables users to video, text and voice chat with the customers, share pictures via broadcast videos, play games and use whiteboards. Primary features of CometChat include WebRTC, file sharing, screen sharing, real-time language translation, customization for layouts, languages and colors, typing indicators, last-seen notifications, read receipts, emojis and stickers. The platform also allows users to switch from text chatting to a video chatting interface. Additional services of CometChat include broadcast messages, guest login support, earlier messages, blocking or unblocking users, video broadcasting and voice notes. Pricing of the product is based on monthly active users and support is extended via email and phone.

Create a scalable voice experience with the API that connects millions globally. With Twilio Voice, you can build unique phone call experiences with one API, to create, receive, control and monitor calls with just a few lines of code. Customize your experience the way you want by using a wide range of customization resources, such as our Voice SDK, speech recognition, Interactive Voice Response (IVR), and recording transcriptions. Whether you're looking to set up global conferencing or alerts & notifications, Twilio has the support you need for building with Voice, such as our Twilio Runtime and Studio developer tools. Find docs, code samples, and helper libraries to start building today.

Authkey.io stands as an exceptional Enterprise Omni Channel API platform, offering an extensive suite of communication tools and APIs meticulously designed to empower businesses in their quest for efficient and secure customer engagement. SMS API:A seamless communication symphony with its event-based messaging prowess. This facet encompasses the seamless orchestration of Bulk SMS delivery, transactional messages, one-time passwords (OTP), and the authentication process through call-based interfaces. Voice API: This dynamic capability ensures the delivery of OTPs through vocal messages, providing an alternative avenue that ensures the recipient's prompt access. Email API: Reliable and rapid delivery of emails, serving critical functions such as password verification, account creation, OTP distribution, and email validation. WhatsApp Business API: The contemporary business landscape requires a direct conduit to reach the massive audience on the WhatsApp API facilitate this engagement, enabling businesses to establish a direct line of communication with their audience. Two-Factor Authentication (2FA) API: Seamlessly dispatching OTPs, verifying logins, and bolstering the security architecture of business software, CRM systems.

You don't have to spend months creating in-app messaging feeds and messaging. Instead, you can implement them in as little as a matter of weeks using Stream's activity feeds or in-app chat APIs. Stream's flexible UI kits, reliable APIs, and developer-friendly SDKs allow product teams to quickly integrate polished communication functionality found on social media platforms like Instagram, Facebook Messenger, or WhatsApp. Stream's APIs have an industry-leading 99.999% uptime guarantee, more than a billion users, and 5,000,000 concurrent connections. This makes them highly scalable and ideal for both enterprise-grade businesses as well as growing startups. Easy-to-use software components make it easier to ship fully-featured activity feeds, in-app chat functionality, and other features faster. This gives your product an edge.

With over 700 direct carrier connections and 60+ offices on 6 continents, Infobip is a global leader in omnichannel communication. We make it our business to simplify how brands connect with, engage and delight their customers at global scale. Our programmable communications platform delivers a suite of tools for advanced customer engagement and support, plus security and authentication. We make this available to you across the widest range of communication channels possible. THE INFOBIP ADVANTAGE (1) Personalized omnichannel customer connections Achieve deeper customer engagement across the widest selection of local and global channels, including: SMS, RCS, WhatsApp, voice, video, email and the most popular chat apps. (2) Global reach, local presence Our 60+ offices around the world allow us to react faster. We provide 24/7 customer support, technical solutions in-line with needs and local requirements — based on proven best practices. (3) Full stack customer engagement Deliver better outcomes for your business by enhancing your communications with fully integrated contact center, marketing automation, and chatbot building solutions informed by our customer data platform.

mesibo allows you to quickly add powerful real-time messaging, group chat and voice, as well as video calls, to your mobile and web apps. When designing mesibo APIs, the main objectives were reliability, performance, as well as scalability. APIs can be as complex as the universe, making apps unnecessarily complicated and error-prone. Instead, we have worked hard to make mesibo APIs simple and powerful. This section will discuss mesibo's real-time APIs in greater detail. To learn more about APIs, it is recommended that you refer to the source code for one of the mesibo samples apps on GitHub. This makes it easier to write cross-platform code on any platform. We will now describe APIs using name and parameters in the sections below.

A flexible communications cloud with advanced APIs to voice and SMS Video and audio designed by the original geeks in software-defined telecom.

Exotel is a cloud-based business phone system that is reliable and secure. It is easy to set up. No additional infrastructure or equipment is required. It allows sales and support teams to work from anywhere. Your customers will enjoy a personalized calling experience. Exotel's drag-and-drop builder makes it easy to track, manage, and build call flows. Easy setup of SMS campaigns. We guarantee the best delivery rates. Delivery to more than 190 countries. Easy user verification via SMS and calls. The best success rates and non-intrusive.

Global SMS/RCS and voice-cloud communications allow you to deliver timely, personalized information. Get a deeper understanding of customers using actionable global phone numbers and subscriber data intelligence. TeleSign's Messaging API allows you to code once and send messages to your customers at scale. It also supports waterfall delivery between channels. TeleSign Messaging API supports SMS, RCS and WhatsApp, allowing you to create secure digital communications that can connect you with customers around the globe. Integrate a single MessagingAPI to send secure, reliable SMS, RCS, and WhatsApp messages directly to your customers. You can choose one or all of these channels to expand your programmable messaging strategy. Reach more customers through 120+ optimized points of presence and 700+ direct to-carrier routes