Best Voice Calling API & SDK Providers with a Free Trial
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Compare the Top Voice Calling API & SDK Providers with a Free Trial as of November 2026
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What are Voice Calling API & SDK Providers with a Free Trial?
Voice calling API and SDK providers offer developers with the necessary tools to integrate voice calling functionality into their applications. These providers typically offer a range of options, including APIs that allow for an easy integration process, as well as SDKs that provide more advanced features such as call recording and real-time transcription. They also often provide comprehensive documentation and technical support to assist developers in implementing these services. Some of the major players in this field include Twilio, Voximplant, and Nexmo, each offering their own unique set of features and pricing plans. In general, these providers aim to make it easier for businesses to incorporate voice calling capabilities into their products without having to build them from scratch. Compare and read user reviews of the best Voice Calling API & SDK providers with a Free Trial currently available using the table below. This list is updated regularly.
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1
Sendbird
Sendbird
Sendbird’s Voice and Video APIs empower businesses to integrate high-quality, real-time voice and video communication into their apps. With support for both direct and group calls, these APIs provide a rich set of features such as video mirroring, call muting, and screen sharing, ensuring a seamless and interactive user experience. The platform supports multi-device and cross-platform capabilities, along with strong security features like media stream encryption and HIPAA compliance. Ideal for industries such as healthcare, e-commerce, and social platforms, Sendbird enables businesses to create engaging and secure communication solutions without complex development overhead.Starting Price: $399/month -
2
ClickSend
ClickSend
ClickSend is a simple, global SMS platform built for developers and the businesses they support. Built on a battle-tested API that always delivers with: - Billions of messages delivered globally - Direct routes only to 190+ countries - 99.95%+ uptime - Lightning-fast delivery - Pay-as-you-go pricing — no lock-ins - 24/7 support from people who actually understand APIs - It works straight out of the box — and keeps working as you scale. Already use Zapier, ActiveCampaign, Make or Power Automate? There are pre-built integrations ready to go. Sign up and send your first message in minutes with free test credits. Perfect for: alerts, 2FA codes, marketing campaigns and transactional messaging.Starting Price: $20 minimum topup -
3
MirrorFly
CONTUS TECH
MirrorFly is a CPaaS platform that empowers businesses and enterprises to add real-time chat features to any app. MirrorFly CPaaS offers chat, voice, video,& broadcasting in an enterprise-grade infrastructure. MirrorFly AI Voice Agent solution is uniquely built for developers who want more than basic communication – specifically for businesses that want to go AI-driven Startups and large enterprises can build their own chat app with extensive customization and branding capabilities to add logos, brand color, and other brand elements. The self-hosted Chat APIs and SDKs offer 1000+ in-app messaging features with 100% customization. In addition, MirrorFly offers a dedicated developer team to support the end-to-end custom chat app development process. MirrorFly Readymade SDKs: 1. In-app Chat API 2. HD Video Call Solution 3. HQ Voice Call SDK 4. Self-hosted Chat Messaging Solution 5. SIP & VoIP Call Solution 6. AI Voice Agent 7. AI Chat BotStarting Price: $299 per month -
4
Twilio
Twilio
Design and deploy your ideal customer engagement experience. Twilio is a single fully-programmable platform with flexible APIs for any channel and over 400+ integrations, backed by a community of over 9 million developers. Build accurate and personalized experiences for your customers, easily and at scale, using SMS and WhatsApp messaging, voice, video, email, and more. 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. Sign up and start building today.Starting Price: $0.0085 per min -
5
EnableX Communications APIs
vCloudx
EnableX makes integrating real-time communications into applications and workflows a lot easier. Designed and developed for Service Providers, Systems Integrators, and Developers, it provides a robust, scalable and secure communications platform without the complexity of building and maintaining the network infrastructure. By simply leveraging on EnableX comprehensive sets of programmable APIs and SDKs, developers can rapidly customize and embed all or part of the communication functions – voice, video, SMS and chat – right into existing applications, workflows and systems. Together with the Virtual Number services and advanced features such as AI and NLP, businesses can reach customers globally with an outstanding communication experience. -
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Plivo
Plivo
Access high-quality cloud communications at a low cost with Plivo Communications Platform, a Cloud API Platform and a Global Carrier Services Provider. Plivo Communications Platform enables users to make phone calls to all countries, buy local phone numbers in 55 countries, send SMS to all countries, and more. Available 24/7, Plivo Communications Platform also features free tech support by experts that are happy to assist customers with their issues.Starting Price: $.005 / SMS -
7
AVOXI
AVOXI
The effective, affordable, and easy-to-use cloud-based call center software, AVOXI Genius. Easily manage your business communications from an intuitive, web-based contact center. AVOXI Genius is the first platform to integrate your contact center solution with your voice service, with virtual phone numbers available for instant activation in 170+ countries. With plans starting at $19.99 per user, AVOXI Genius is one of the most affordable solutions worldwide! Get 2 months free--limited time only.Starting Price: $19.99/month/user -
8
CometChat
CometChat
CometChat is a chat API and in-app messaging SDK (software development kit) that enables users to integrate HD voice and video calling, as well as text chat functionality directly into their mobile and web apps. CometChat also supports features such as push notifications, read receipts, typing indicators, real-time translation, and more. CometChat allows users to create their own user interface for private or group chat applications. Customization tools let users personalize various elements of their chat app. The platform also provides users with the tools to add voice, and video calling and conferencing capabilities to their apps or websites. Users can also send and receive media files through CometChat, as the platform enables users to sync and share files like GIFs, photos, videos, and audio clips. Support for custom payloads mean users can send calendar invites, or share information like their location or event details to chat participants.Starting Price: $109.00/month -
9
Twilio Voice
Twilio
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. Create an engaging voice experience that you can quickly scale and modify with a wide array of customization options and resources, like our Voice SDK. Then, add on features like Interactive Voice Response (IVR), recording transcriptions, and speech recognition to create an experience that your customers will appreciate. Whether you're looking to set up global conferencing or alerts & notifications, Twilio has the support you need for building with Voice. Find docs, code samples, helper libraries, and developer tools such as Twilio Runtime and our visual workflow builder, Studio.Starting Price: $0.0085 per min -
10
Authkey
Authkey.io
Authkey is a multi-channel CPaaS platform providing SMS API, WhatsApp Business API, Voice API, Email API, and Google RCS. It helps businesses send notifications, promotional messages, transactional messages, OTPs, 2FA, and more. Designed for responsiveness and ease of use, Authkey allows you to start without adding any credit cards. Authkey offers a free sandbox account for building, testing, and deploying. It supports easy-to-integrate APIs for all channels and over 1,000 automation options via Zapier, Pabbly, Integrately, and other partners. You can easily push bulk campaigns through all channels. WhatsApp Chatbot for intelligent customer query responses. Join over 200 active businesses working with us and grow together.Starting Price: $0 -
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VaxVoIP SIP Phone SDK
VaxSoft
VaxVoIP SIP Phone SDK helps developers build branded SIP softphones and VoIP applications for Windows, Android, iPhone, and iPad. It provides SIP signaling, media handling, and call-control APIs for voice and video, messaging, presence, multiple SIP accounts, and concurrent call lines. Features include conferencing, call hold, transfer and forwarding, WAV call recording, SIPREC client support, echo cancellation, jitter buffering, and answering-machine detection. Sample projects cover C#, VB.NET, WPF, Visual C++, Delphi, Java, Objective-C, and Swift, with platform-specific documentation. The SDK connects applications to standards-based SIP servers, IP-PBX systems, gateways, and telephony providers. Use cases include softphones, mobile VoIP apps, call-center tools, auto-dialers, and embedded business communications. A fully functional 30-day trial is available; annual licenses are sold separately for Windows, Android, and iOS.Starting Price: $2,640/year -
12
Stream
GetStream.io
Why spend months building in-app activity feeds and messaging from scratch when you can implement in just weeks with Stream's activity feeds and in-app chat APIs? Stream's reliable APIs, developer-friendly SDKs, and flexible UI kits enable product teams to quickly integrate polished communication functionality often found in social media platforms such as WhatsApp, Facebook Messenger, and Instagram. With an industry-leading 99.999% uptime SLA, over a billion end users, and 5 million concurrent connections recently supported in a single chat channel, Stream's APIs are highly scalable, making them ideal for enterprise-grade businesses and growing startup platforms alike. Ship fully-featured activity feeds and in-app chat functionality faster with easy-to-use software components that give your product a competitive edge. -
13
QuickBlox
QuickBlox
QuickBlox is an AI and communication platform for adding AI agents, in-app chat, voice calling, and video calling to Android, iOS, and web apps. The AI Agent Platform lets you deploy conversational AI agents that answer questions, collect information through AI-powered forms, automate workflows like patient intake, and hand off to a human when needed. The chat API and messaging SDK support one-to-one and group chat, file sharing, and push notifications, with UI Kits for iOS, Android, and JavaScript. The video SDK delivers one-to-one and group video and voice calls built on WebRTC. Q-Consultation is a white-label telehealth app combining HIPAA-compliant video, secure chat, and AI-powered patient intake under your brand. Trusted by healthcare businesses, from telemedicine startups to large enterprises. QuickBlox is SOC 2 Type 2 certified and offers a HIPAA Cloud plan with a BAA, plus dedicated cloud or on-premises deployment for Enterprise customers. Start with a free 30-day trial.Starting Price: $107 per month -
14
Zernio
Zernio
Zernio is a unified social media API platform that enables developers and AI agents to publish, schedule, and manage content across 14+ social networks through a single integration. Instead of building separate integrations with each platform, developers make one API call and Zernio handles authentication, media formatting, rate limits, and platform-specific requirements. The platform supports post scheduling, content management, comments and DMs automation, analytics tracking, ads management, and media uploads. It integrates with Instagram Business and Creator APIs, TikTok Business API, LinkedIn, YouTube, Twitter/X, Facebook, Pinterest, Reddit, Threads, Bluesky, and WhatsApp Business API. Features include automatic token refresh, webhook notifications, and rate limit management. Built for SaaS companies, agencies, and AI agent builders, the product is fully white-label.Starting Price: $19/month -
15
VaxVoIP WebPhone SDK
VaxSoft
VaxVoIP WebPhone SDK is a software development kit for adding browser-based communications to websites and applications. It combines an HTML/JavaScript webphone with a ServerWebRTC COM component that bridges WebRTC clients to SIP servers and IP-PBX systems, allowing teams to build browser softphones, click-to-call features, customer-portal calling and contact-center applications without replacing their telephony infrastructure. The SDK supports real-time audio and video, text chat and screen sharing in Chrome, Firefox, Safari and Microsoft Edge. Developers can use technical documentation, a 30-day fully functional evaluation, and sample projects for C#, Visual Basic .NET and Visual C++. Commercial licenses cover one service and server with unlimited concurrent calls, and include technical assistance, updates, new releases and maintenance during the license term.Starting Price: $6,240/year -
16
Infobip
Infobip
Infobip is a global leader in omnichannel engagement powering a broad range of messaging channels, tools and solutions for advanced customer engagement, authentication and security. With over 700 direct carrier connections and 60+ offices on 6 continents, Infobip is the #1 choice of some of the world's biggest companies to scale their customer communications. We help our clients and partners overcome the complexity of consumer communications, grow their business and enhance customer experience, all in a fast, secure and reliable way. With Infobip, you can achieve deeper customer engagement across the widest selection of local and global channels, including: SMS MMS RCS Live Chat WhatsApp Business Apple Messages for Business Facebook Messenger Instagram Business Telegram Viber Voice / VOIP Video Email -
17
mesibo
mesibo
mesibo is a powerful real-time communication platform to quickly add robust real-time messaging, group chat, voice, and video calls, conferencing into your mobile and web applications. The key objectives while designing mesibo APIs were reliability, performance, and scalability. We have seen APIs as complex as the universe making apps unnecessarily complex and error-prone. We have instead worked hard to make mesibo APIs simple, yet powerful. In this section, we will explore mesibo real-time APIs in detail. It is highly recommended that you also refer to the source code of one of the mesibo sample app in GitHub to learn how APIs are used. This makes it easy for you to write cross-platform code across platform. In the following sections, we will describe APIs with name and parameters. -
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TeleSign
TeleSign
Deliver timely, personalized information through global SMS/RCS and voice cloud communications. Gain a deeper understanding of your customers from actionable global phone number and subscriber data intelligence. Code once and message your customers at scale using TeleSign’s Messaging API - complete with waterfall delivery between channels. TeleSign Messaging API includes SMS, RCS, and WhatsApp to help you build secure digital communications that connect you with your customers anywhere in the world. Integrate a single Messaging API and start sending reliable, secure SMS, RCS and WhatsApp messages to your customers today. Choose one or all three channels to broaden your programmable messaging strategy and expand your audience. Reach more customers with 120+ optimized points-of-presence and 700+ direct-to-carrier routes. -
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SignalWire
SignalWire
An elastic communications cloud with advanced APIs for voice, SMS and video designed by the original geeks of software-defined telecom. When your audience is large, your brand is premium, and you won't settle for janky video conferencing UX, you want this. Real time, granular control over call flows, routing, and codecs. 300% more responsiveness than you get with REST. If you use AI in your voice apps, you just found your new favorite API. If you're more comfortable with REST than WebSockets or already use TwiML, these APIs are like TwiML...if TwiML suddenly knew Kung Fu. The SMS API makes it easy to move your expensive SMS traffic to SignalWire and cut your billio 50-80% in the process. Launch and scale communication products on infrastructure built for this decade and the next rather than running aground on the limitations of 2010s-era SaaS. Persistent, bi-directional connections between your video and voice apps and our infrastructure means 300% more responsiveness. -
20
Exotel
Exotel
Exotel is a secure and reliable business phone system on the cloud. Simple to setup. No additional infrastructure or equipment required. Enables sales and support teams irrespective of where they work from. Build a personalized calling experience for your customers. Track, manage and build call flows using Exotel with our drag-drop builder. Set up SMS campaigns with ease. We promise you the best delivery rates. Delivery to over 190 countries. User verification made seamless over calls & SMS. Non intrusive, with the best success rates. Make it easy for your agents to make sales calls to prospective customers. Automated dialers, integrations with CRMs, etc. make it a productive experience for your sales teams. -
21
Sinch
Sinch
Sinch is a cloud communications platform that enables businesses to communicate with customers through SMS, MMS, RCS, WhatsApp, email, voice, and other digital channels. The platform provides communication APIs and ready-to-use applications for marketing campaigns, transactional notifications, customer support, and identity verification. Its messaging capabilities support personalized text campaigns, two-way conversations, automated reminders, and rich media interactions across global mobile networks. Sinch also offers email delivery services, programmable voice calling, phone number management, and authentication tools for securing customer accounts. AI-powered capabilities include conversational chatbots, customer service automation, fraud prevention, and intelligent communication workflows. The platform integrates with business applications through REST APIs, SDKs, and prebuilt integrations while providing delivery analytics, communication management, and enterprise security.
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