Best Free Voice Calling API & SDK Providers of 2025

Bird (formerly MessageBird), the next-generation CRM, is a powerful tool for marketing, sales, and payments. It powers over 5 trillion messages per year across Email, WhatsApp, and SMS. Bird helps leading brands grow more cost-efficiently through personalized interactions via Email, SMS, or WhatsApp. Bird's APIs and applications are used by the most innovative companies in the world to build communication solutions. Start today and communicate with your customers on any channel, for any purpose, anywhere in the globe. Marketing messages, push notification, order updates, shipping alerts, and more. Operational bottlenecks limiting your growth? Automated conversations and workflows can be used to collect critical information, reduce manual tasks, implement Self-Service flows, and route chats directly to the right agent. Our auto-scaling, reliable APIs are available with comprehensive documentation, complete API references, and intuitive SDKs.

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.

Dyte's Video SDK and APIs are SOC 2, GDPR, and HIPAA compliant. Embed scalable, customisable and secure video call into your web or mobile app with just few lines of code. It is compatible with Android, iOS, React Native, Angular and many more languages. With an uptime of 99.99%, industry-leading documentation, UI kit and out of the box plugins, customize the video experience within minutes.

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.

You can save your time building UI and features for your video-calling application. You can integrate video calls into an application with just 5 lines of code. To establish connection between your app and Video SDK, generate an API Key. It allows for secure, end-to-end connection between your app and our servers. Install the JavaScript code on your website. You can create an interactive video calling app in just a few lines of code. Analytics Dashboard allows you to track all usage and provide manual operations control. Everything you need to create custom and branded live shopping experiences at any scale for eCommerce brands. Everything you need to create custom, branded, highly secure telemedicine communication SDKs and APIs at any scale.

ZEGOCLOUD's communication APIs allow you to embed engaging voice, video and in-app chat experiences within your apps. Start with just 4 lines of code. You can then add more features to your interactions. Our SDKs for voice, video, or in-app chat enable you to create the communication features that your users need to communicate, share, and interact with one another anywhere, anytime. A rich collection of add-ons can help you to improve the user experience and increase the emotional responsiveness of your avatars, AI-powered videos effects, whiteboards, etc. Our powerful monitoring and analytics tools allow you to monitor the quality of communications and gain insight into your users' experience. This will enable you to quickly respond to any issues and improve your services. ZEGOCLOUD's social tools allow you to create 1-on-1 and group video chats, live audio rooms, social live streaming, and live audio rooms in your apps. This will help your users connect and have fun.

QuickBlox chat API & SDK allows you to create your own messenger that supports video calling and chat. QuickBlox offers instant messaging APIs that allow chat and calling functionality for any Android, iOS, and Web application. All the features you need to create a great messaging app. WebRTC allows for high quality group and one-to-one calling. Flexible data and file storage to complement your messaging. Real-time notifications and alerts make it easy to integrate your business processes. All file types can be shared and linked (images, audio and video, as well as docs and other file formats). QuickBlox messaging API is used by over 30,000 software developers worldwide. QuickBlox is a HIPAA compliant chat solution that is trusted by healthcare businesses around the world. We serve many customers, from large corporations that store millions of records regarding healthcare and insurance to startups who entrust their telemedicine communications to us.