Best Voice Calling API & SDK Providers for Workers by Delos

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.

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.

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.

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.

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.