Best Voice Calling API & SDK Providers for WhatsApp

Sendbird’s Voice and Video APIs give companies the tools they need to incorporate top-notch, real-time voice and video communication into their applications. These APIs accommodate both one-on-one and group calls, offering a comprehensive array of features, including video mirroring, call muting, and screen sharing, to deliver a smooth and interactive experience for users. The platform also boasts multi-device and cross-platform functionality, along with robust security measures such as media stream encryption and compliance with HIPAA regulations. Perfect for sectors like healthcare, e-commerce, and social networking, Sendbird allows businesses to develop engaging and secure communication solutions without the burden of complicated development processes.

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.

Telnyx is a real-time communications and AI infrastructure platform built to help businesses develop and deploy voice, messaging, and AI-powered conversational systems on top of a globally owned telecom network. Unlike traditional communication providers that rely heavily on rented infrastructure, Telnyx operates its own carrier-grade network stack, including physical interconnects, edge processing systems, mobile core infrastructure, and AI inference layers. This full-stack ownership allows the platform to deliver low-latency voice AI, programmable identity verification, autonomous orchestration, and real-time communication services without depending on external telecom providers. Telnyx provides developers and enterprises with tools such as voice agent builders, speech-to-text, text-to-speech, AI orchestration engines, global phone numbers, programmable compliance systems, and real-time communication APIs for building intelligent automation systems. The platform supports real-time multilingual AI transcription, AI-native routing, and conversational AI deployments powered by colocated GPUs and telecom edge points of presence. Telnyx also includes built-in programmatic compliance capabilities such as 10DLC and KYC automation to help organizations manage regulatory requirements directly within communication workflows. Businesses can use the platform to automate appointment reminders, customer support, financial interactions, retail workflows, automotive operations, and hospitality services through AI-driven voice and messaging agents. The company emphasizes enterprise-grade security with network-level identity verification, fraud prevention, deepfake protection, and compliance certifications including HIPAA, GDPR, PCI, SOC2 Type II, and ISO standards.

Bird, previously known as MessageBird, represents the future of CRM tailored for Marketing, Sales, and Payments, facilitating more than 5 trillion messages each year across platforms like Email, SMS, and WhatsApp. Top brands efficiently enhance their growth through Bird by engaging in tailored interactions across these channels. Innovative organizations around the globe utilize Bird's robust applications and APIs to create effective communication solutions. Start your journey today and connect with your customers seamlessly across various channels, catering to diverse use cases regardless of location. You can send marketing messages, push notifications, order confirmations, delivery updates, and much more. If operational challenges are hindering your growth, leverage automated conversations and workflows to gather essential information upfront, minimize manual tasks, establish self-service options, and direct chats to the appropriate agents. With our dependable, auto-scaling APIs, you can quickly get started with extensive documentation, comprehensive API references, and user-friendly SDKs at your disposal. Experience the power of streamlined communication and watch your business thrive.

Connect with your customers like never before across all channels. With CPaaS and APIs for SMS, Voice, Video, and Verification, you can reach any mobile device globally in mere seconds. By effectively engaging your customers, you can significantly increase webshop orders, a fact proven by our collaboration with a leading telecommunications company that utilized a user-friendly online chatbot. Additionally, we assisted a prominent automotive firm in re-engaging potential buyers who had not responded to emails, leading to impressive results from their tailored Rich SMS campaign. Are your clients missing important appointments? Implementing engaging SMS reminders not only benefits them but also enhances your revenue streams. Trusted by developers worldwide, our solutions allow you to build with assurance and elevate your business using just a few lines of code. Strengthen your connection with customers and enhance their journey at every touchpoint, ultimately driving greater satisfaction and loyalty. Embrace this opportunity to transform your customer interactions and watch your business thrive.

Provide prompt and tailored communication through international SMS/RCS and voice cloud services. Enhance your customer insights with actionable intelligence derived from global phone numbers and subscriber data. Utilize TeleSign’s Messaging API to code once and effectively reach your audience at scale, leveraging seamless delivery across various channels. The TeleSign Messaging API supports SMS, RCS, and WhatsApp, empowering you to create secure digital interactions that engage customers globally. By integrating a unified Messaging API, you can begin dispatching dependable and secure messages via SMS, RCS, and WhatsApp to your clientele today. Opt for one, two, or all three channels to diversify your programmable messaging approach and broaden your reach. With over 120 optimized points-of-presence and more than 700 direct-to-carrier routes, connect with an even larger customer base effortlessly. This expanded network ensures your messages are delivered efficiently and effectively.

DecisionTelecom is an international provider of Application-to-Person (A2P) messaging and voice communication solutions, delivering a comprehensive omnichannel platform for business messaging on a global scale. As a certified telecommunications operator, they maintain direct connections with mobile network operators, which facilitates the efficient delivery of messages in over 190 countries. Their extensive range of services encompasses SMS, Viber, WhatsApp Business messaging, RCS, and high-quality voice calls, all available through accessible APIs and SDKs that simplify integration with current systems. The goal of Decision Telecom is to improve and streamline interactions between businesses and their customers, offering 24/7 expert support along with tailored account management to guarantee dependable and effective service. By prioritizing user experience, they ensure that organizations can communicate effortlessly and effectively with their clientele.

Crafting Customer Journeys Through Meaningful Conversations. Delivering compelling experiences that align with your customers' needs. Favored by developers and designed for enterprises. Vonage Communications APIs (previously known as Nexmo) empowers emerging startups and nimble organizations to elevate customer interactions and achieve significant business results at scale. With our user-friendly APIs, comprehensive global platform, and dedicated support, you can simplify communication complexities and drive innovation at a quicker pace. Rethink voice communication to transform how your customers engage with your brand. Each message can become a pivotal moment for both your customers and your organization. Advance security and privacy measures while providing smooth login experiences. Develop contemporary, high-quality voice applications hosted in the cloud. Effortlessly send and receive SMS messages in nearly every nation worldwide. Access real-time insights on any phone number across the globe. Initiate and receive calls using your current VoIP system, all from the cloud, ensuring flexibility and efficiency. This holistic approach not only enhances user engagement but also fosters long-term relationships with your audience.

Numerous companies depend on our cloud communication platform to enhance their relationships with customers. This Communication Platform integrates cutting-edge technologies, offering a comprehensive solution that serves as a dependable resource for digital transformation and worldwide connectivity. You can send marketing promotions, push notifications, delivery confirmations, order updates, and conduct data surveys—essentially, anything you can envision. Leverage rich media chat and chatbots to empower your teams and meet every client's requirements at any time and from any location. You will have access to an extensive collection of API references, enabling you to customize and build workflows tailored to your needs. Moreover, you can safeguard user identities and accounts against online fraud with robust two-factor authentication and smooth verification processes. Ultimately, our platform ensures a seamless communication experience that drives engagement and fosters growth.