In-App Voice calling

Have your customers at hello with flexible in-app voice calling

Build trust and meaningful customer relationships while keeping costs down, and scale as you go with our flexible in-app calling solution. With our scalable in-app voice calling SDK, youā€™ll have them at hello!

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Join over 150,000 businesses, including 8 of the 10 largest tech companies in the world.

Hassle-free, scalable calling experience

Level up user experience

Get real-time insights into caller identityĀ andĀ historyĀ for quicker,Ā personalizedĀ problemĀ solving.

Connect with confidence

Connect users without revealing phone numbers, keep identities secure, and transactions on-platform.

Future-proof your business

Upgrade your in-app contact center and CRM platform with high-quality in-browser calling in no time!
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Cost-effective, high-quality calling

Everyone loves crisp, high-quality calls, and now you can have them all the time, both app-to-app and app-to-phone. Built with users in mind, our APIs and SDKs are scalable, flexible,ā€Æand super easy to use. 

We use our industry-leading infrastructure, enterprise-grade platform, and data-optimized routing to power calls across the globe. Give your calls the quality they deserve! 

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Smooth real-time communication

Easily integrate voice to your app using our SDKs for iOS, Android, and Javascript, and expand globally without expensive telecom infrastructure. 

Identify callers and add context to calls with metadata for a smoother customer experience. While you’re at it, make the most of our WebRTC – weā€™ve spent the last ten years fine-tuning it to perfection, just for you! 

                            

                                $client = new Clx\Xms\Client("{spid}", "{token}");
                    $batchParams = new \Clx\Xms\Api\MtBatchTextSmsCreate();
                    $batchParams->setSender("12345");
                    $batchParams->setRecipients(["46123123123"]);
                    $batchParams->setBody("Hello, World!");
                    try {
                        $result = $client->createTextBatch($batchParams);
                        echo("Successfully sent batch " . $result->getBatchId());
                    } catch (\Clx\Xms\ApiException $ex) {
                        echo("Failed to communicate with XMS: " . $ex->getMessage() . "\n");
                    }
                            
                        
                            

                                const targetPosition =
                    element.getBoundingClientRect().top + window.pageYOffset + offset
                    const startPosition = window.pageYOffset
                    const distance = targetPosition - startPosition
                    // Initialize a start time for the animation
                    let startTime = null
                    
                            
                        

Build a killer call experience

Build your app, and start making calls in minutes! Use our iOS, Android, or JavaScript SDKs combined with our sample app code and documentation to get started today.

Connect with customers around the world in seconds

Cross-platform support

Call anyone with a connection, regardless of the platform they use – our SDKs cover iOS, Android, and Javascript.

Peer-to-peer communication

Send data directly to the receiver. Less time traveling means better quality, and we always take the fastest route.

Global reach

Weā€™ve got regional data centers in every corner of the world, ensuring global reach with the lowest possible latency.

Easy integration

Add voice and video calling to apps or web browsers in no time with our SDK.

Pay as you go

No hidden charges, no upfront payment – pay for what you use, when you use it.

End-to-end encryption

BuildĀ trust and protectĀ customers and staff – privacy and security guaranteed.

Enterprise-grade reliability

Make the most of our cloud-based in-app calling platform – itā€™s secure, stable, and 100% future-proof.

Got questions? We’ve got answers!

Sinch In-App Voice Calling uses the WebRTC framework – the most frequently used voice and video calling technology for IP-based communication. WebRTC combines multiple technologies to ensure the best call quality around.

Our technology supports multiple protocols, but we mostly use OPUS. It’s a flexible auto-codec that adapts voice quality to suit network quality – a good connection results in HD voice quality. 

The video codec we mostly use is VP8.ā€Æ 

Sinch powers all kinds of applications, from MVP prototypes to successful and widely used applications. Our services scale on demand and offer high availability at all times.

It depends on the type of calls – voice app-to-app, video app-to-app, or app-to-phone. Need more details? Contact us to get a copy of our guide!

The Sinch SDK uses P2P for the voice stream when possible. We use the ICE standard for NAT traversal. If a P2P channel isnā€™t possible – for example when both sides are behind a symmetric NAT – the voice channel will fall back to Sinch media proxies. 70-75% of calls made will go over P2P, and 25-30% will go through servers due to firewall restrictions.

Insights from Sinch

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STIR/SHAKEN

Fight back against robocalls, increase call answer rates, and build consumers’ trust.

What are you waiting for?

Start building conversations now!

Sinch makes it easy!

Build meaningful connections with your customers.