Voice Calling 1 Voice Calling 2 Voice Calling 3

Voice Calling

With new expertise from our Sinch team, we are able to provide you the very latest in Voice products and technology.

Read about the Sinch acquisition here.

  • Viber
  • Loreal
  • Microsoft
  • Renault

New Voice Capabilities

Easily add crisp HD quality VoIP calling to your applications, by connecting to our Voice APIs and using WiFi calling, PSTN origination and termination, or the new Voice verification services. Add voice calling for better app engagement, stickiness, and increased user retention. Our voice services are built on the same carrier-grade platform as our leading messaging services.

CLX offers competitive pricing for our Voice product. Find out more on our Pricing page.


Voice Products

  • App to Phone calling

    App to Phone calling

    Calling from your app to landline and mobile phone numbers with PSTN termination.

  • Phone to Phone (Anonymous) calling

    Phone to Phone (Anonymous) calling

    Anonymous and international calling with local DIDs across markets.

  • App to App Calling

    App to App Calling

    In-app voice calling over a data connection.

  • Carrier Grade Platform

    Carrier Grade Platform

    Our voice services are built on a carrier-grade platform used by 70+ mobile network operators world wide.

Leading Voice Technology

HD Voice Codec

We improve upon the HD Opus Voice Codec with automatic and adaptive configuration to adjust latency and audio quality according to network speed to optimize sound. Using FEC (forward error correction), we send redundant data so that the receiver only recognizes the data portion that is error-free.

PSTN Routing

Our direct connections with aggregators maximize routing for the best quality connections at all times. Monitoring traffic 24/7, we engage in early detection of connection issues or reduced quality and re-routes traffic accordingly, ensuring the best in quality.

Call Setup Speed

With low latency call setup, the receiver to be notified under a second of an incoming call when using our active connection technology and in 1-3 seconds using push notifications. This is superior to standard protocol for VoIP, which results in call setup times of 2-5 seconds.

Voice Features

DID Management

Manage DID rentals in the dashboard with auto-renewal for ease of maintenance and no service interruptions. 

Voice Encryption

All voice streams are encrypted end-to-end.

Reach Global Markets

Reach markets in every country across the globe by enabling users to contact their friends and family via voice.

Fast Connect

Significantly reduce call setup times by 50%.

Push Notifications

Send Push Notifications directly from the SDK for seamless communication in the foreground and background.

Cross-Platform Support

SDKs currently available for iOS, Android and Javascript platforms, with back-end services exposed over REST APIs, primarily for back-end-to-back-end integration. 


Not Ready Yet?

Not ready yet?  Talk to one of our experts at Sinch!

The CLX Difference

  • World Class Cloud Communications Platform

    • Programmable Cloud APIs

    • Security & Compliance

    • Succeed at Scale

    • Optimized to Deliver

  • Tier 1 Super Network

    • Deep Carrier Integration

    • Lowest Latency

    • Secure Data

    • Direct Escalation if Things Go Wrong

  • Our People

    • Market Experts

    • Passionate about Service

    • Can be Trusted to Do the Right Thing

    • Obsessed with Automation & Efficiency

What Our Customers Say About Us

  • Customer Proof verified by TechValidate.

  • Customer Proof verified by TechValidate.

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