Level up user experience

Get real-time insights into caller identity and history for quicker, personalized problem 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, and 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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video call
carbon apps
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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 - we’ve spent the last ten years fine-tuning it to perfection just for you! 

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.


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

We’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.

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Pay as you go

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

End-to-end encryption

Build trust and protect customers and staff - privacy and security guaranteed.

Enterprise-grade reliability

Make the most of our cloud-based in-app calling platform - it’s secure, stable, and 100% future-proof.

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Got questions? We've got answers!

  • Which technology do you use for making calls?

    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.

  • Which codec do you use, and do you use WebRTC?

    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.  

  • What scalability options does Sinch offer?

    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.

  • How much mobile bandwidth does the Sinch SDK use?

    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!

  • Does the Sinch SDK work behind symmetric NATs?

    The Sinch SDK uses P2P for the voice stream when possible. We use the ICE standard for NAT traversal. If a P2P channel isn’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.

Our pricing page is on the way! In the meantime, get in touch to discuss pricing

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Voice API

Design the exact voice call flow you need with flexible and scalable solutions.

Number Masking

Masking numbers to anonymize voice calls can protect you and your customers while keeping personal numbers safe.


Fight back against robocalls, increase call answer rates, and build consumers' trust.
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What are you waiting for? Start building conversations now

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