List of the Top 9 Free Voice Calling API & SDK Providers in 2025

Welcome to TENIOS, the cloud communications provider under the Apifonica Group umbrella. Based in Germany, TENIOS focuses on innovative AI voicebots and telephony solutions designed for businesses. Their succinct mission is to deliver Conversational AI to the global market. Driven by a passion for automation, a dedicated team of specialists in Cloud Technology, Telephony, and AI collaborates to enhance business communication and streamline related workflows. TENIOS Voicebots efficiently manage both outbound and inbound calls, follow up with leads, pre-qualify them, update CRM data in real-time, and generate reports to enhance customer communication strategies. Their all-encompassing telecom platform provides a variety of services, including virtual phone numbers, smart call routing, interactive voice response (IVR) systems, SMS, RCS, and a powerful Voice API for the smooth integration of voice applications. With more than twenty years of industry experience and hosting services based in Germany, TENIOS guarantees dependable and scalable communication solutions that are customized to accommodate a wide array of business requirements. Additionally, their commitment to innovation positions them as a leader in the evolving landscape of cloud communications.

Bird, formerly known as MessageBird, is a state-of-the-art CRM designed specifically for Marketing, Sales, and Payments, processing more than 5 trillion messages each year through various channels such as Email, SMS, and WhatsApp. Leading brands are leveraging Bird to drive their growth by facilitating personalized interactions through these platforms. Global innovators utilize Bird’s wide range of applications and APIs to develop effective communication strategies. Start your journey now and connect with your customers on any platform, catering to numerous use cases worldwide. Whether your needs involve marketing messages, push notifications, or tracking order and delivery updates, Bird is equipped to meet those demands. If operational challenges are stalling your growth, enhance your processes with automated dialogues and workflows that collect vital information efficiently, reduce manual intervention, create self-service capabilities, and route inquiries to the right representatives. With our reliable, auto-scaling APIs, you can easily initiate setup and integration, bolstered by exhaustive documentation, thorough API references, and intuitive SDKs, ensuring a smooth assimilation into your current systems. Embrace the future of communication with Bird and transform how you engage with your audience.

Authkey.io is a remarkable Enterprise Omni Channel API platform that provides a comprehensive array of communication tools and APIs, meticulously crafted to assist businesses in achieving effective and secure interactions with their customers. The SMS API orchestrates a seamless communication experience through event-based messaging, facilitating Bulk SMS delivery, transactional notifications, one-time passwords (OTP), and call-based authentication methods. With its Voice API, businesses can send OTPs via voice messages, ensuring recipients have immediate access to important information through an alternative channel. The Email API guarantees efficient and timely email delivery for essential tasks like password verification, account creation, OTP sending, and email validation. In today's digital environment, the WhatsApp Business API serves as a vital link that allows businesses to connect directly with a vast audience on WhatsApp, thereby enhancing customer engagement. Additionally, the Two-Factor Authentication (2FA) API plays a crucial role in security by efficiently sending OTPs, verifying user logins, and strengthening the security framework of business applications and CRM systems, ultimately fostering a safer digital landscape for organizations. This multifaceted platform empowers enterprises to optimize their communication strategies while reinforcing user trust and security.

Dyte's Video SDK and APIs adhere to SOC 2, GDPR, and HIPAA standards, ensuring a high level of security and compliance. You can effortlessly integrate scalable, customizable, and secure video calling capabilities into your web or mobile applications using only a few lines of code. The SDK supports various platforms, including Android, iOS, React Native, Angular, and numerous other languages. Boasting an impressive uptime of 99.99%, alongside comprehensive documentation, a user-friendly UI kit, and pre-built plugins, you can tailor the video experience to meet your specific needs in just minutes. This flexibility allows developers to enhance their applications quickly and efficiently, providing users with a seamless communication experience.

Accelerate the creation of your video calling application by optimizing the time spent on user interface design and feature development. With just five lines of code, you can effortlessly incorporate video calling functionalities into your project. Start by generating an API Key, which establishes a secure connection between your application and the Video SDK. This configuration guarantees a strong end-to-end encrypted channel between your app and our servers, enhancing security. By adding simple JavaScript code to your website, you'll easily develop a dynamic video calling solution. In only a few lines of code, you can design an engaging video calling application suited to your specific requirements. The Analytics Dashboard further enriches your experience by providing valuable insights into service usage, alongside manual operational control options. You have access to everything required to create personalized and branded live shopping experiences designed for eCommerce businesses of various sizes. Moreover, all essential tools are at your disposal to develop secure telemedicine communication APIs and SDKs, ensuring compliance and safety at any scale. This all-encompassing strategy not only fosters innovation but also allows you to broaden your digital services in a streamlined manner, paving the way for future growth.

Transform your applications by incorporating engaging real-time voice, video, and in-app chat features with ZEGOCLOUD's robust communication APIs. By implementing just four simple lines of code, you can initiate the integration and gain access to a multitude of interactive functionalities. Take advantage of our extensive voice, video, and in-app chat SDKs to customize the communication features that your users crave, enabling them to connect, share, and interact anytime and anywhere. Enhance the user experience with a rich array of add-ons, including emotionally aware avatars, AI-driven video effects, and interactive whiteboards, among others. Ensure high-quality communication in real-time while also acquiring significant insights into user behavior through our sophisticated monitoring and analytics platforms, allowing you to promptly tackle any issues and continuously refine your services. ZEGOCLOUD's pioneering social solutions empower you to establish personalized one-on-one and group video calls, energetic audio rooms, and lively social live streaming, creating opportunities for users to connect and enjoy memorable experiences. By utilizing these tools, you can nurture a thriving community where individuals build lasting bonds and cherish shared moments together, thereby fostering a sense of belonging among users. This integration not only enhances user engagement but also positions your application as a leader in innovative communication solutions.

Infobip stands as a prominent figure in the realm of omnichannel communication, boasting over 700 direct carrier connections and more than 60 offices spread across six continents. Our mission is to streamline the ways in which brands interact with, engage, and captivate their customers on a global scale. Our robust communications platform offers a comprehensive array of tools designed for superior customer engagement and support, along with essential security and authentication features, accessible through a vast array of communication channels. THE INFOBIP EDGE (1) Tailored omnichannel customer interactions Enhance customer involvement through a diverse range of local and international communication options, such as SMS, RCS, WhatsApp, voice, video, email, and leading chat applications. (2) Worldwide influence with localized service With over 60 offices worldwide, we can respond swiftly to client needs. Our team provides round-the-clock customer support, delivering technical solutions tailored to specific local demands, grounded in established best practices. (3) Comprehensive customer engagement solutions Boost your business performance by enriching your communication strategies with our fully integrated offerings, which include contact center capabilities, marketing automation, and chatbot development, all powered by insights from our customer data platform. Additionally, our commitment to continuous improvement ensures that we remain at the forefront of innovation in customer engagement.

Mesibo stands out as a comprehensive platform for real-time communication, allowing for the effortless integration of features such as messaging, group chats, voice calls, and video conferencing within mobile and web applications. In creating the Mesibo APIs, our central aim was to prioritize reliability, performance, and scalability, as we understood that overly intricate APIs could introduce unnecessary complications and higher rates of errors in applications. Instead of adhering to the trend of complex API frameworks, we chose to emphasize simplicity while retaining robust capabilities. This section will explore the detailed workings of Mesibo's real-time APIs. To better understand how these APIs function in practice, it is recommended to examine the source code of one of the sample applications hosted on GitHub, as this will enhance your ability to write cross-platform code seamlessly. Following this, we will provide a detailed overview of the APIs, including their names and parameters, to ensure you have a thorough grasp of their functionalities. Moreover, this knowledge will equip you to effectively implement these APIs within your own projects, thereby maximizing their potential. Understanding the underlying architecture of these APIs will also aid in troubleshooting and optimizing your applications.

Build your personalized messaging platform equipped with chat and video call functionalities in mere minutes by leveraging the QuickBlox chat API and SDK. QuickBlox provides an instant messaging API that effortlessly incorporates chat and calling capabilities into any application, be it for Android, iOS, or web platforms. It includes all the vital features necessary for creating a premium messaging application, offering high-quality one-on-one and group calling experiences supported by WebRTC technology. Moreover, it supplies adaptable data and file storage options that significantly enhance your messaging interactions. You can also seamlessly integrate ongoing business processes with real-time alerts and notifications, as well as share a variety of file formats, such as images, audio, video, and documents. Trusted by over 30,000 developers and organizations worldwide, QuickBlox serves as a HIPAA-compliant chat solution, earning the confidence of healthcare providers globally. This service caters to a broad range of clients, from large enterprises managing substantial healthcare and insurance records to forward-thinking startups that depend on our platform for telemedicine communications. Such adaptability underscores QuickBlox's capacity to fulfill diverse needs across various sectors, ensuring that users have access to reliable and effective communication tools. In a rapidly evolving digital landscape, QuickBlox stands out as a robust choice for those looking to innovate their messaging solutions.