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LISNR Launches Next Generation Ultrasonic SDK for Radius

ultrasonic waves
LISNR announced the launch of Radius 3.1, the next generation of its ultrasonic software development kit (SDK).
Bryant Chan
May 20, 2025
2 minutes

Powering a New Standard for Secure Proximity Authentication & Engagement in Unified Consumer Experiences

Cincinnati, OH— May 20, 2025— LISNR®, the global leader in proximity engagement solutions, announced the launch today of Radius® 3.1, the next generation of its ultrasonic software development kit (SDK). With this release, LISNR expands its core technology to deliver a more complete, real-world solution for proximity-based authentication and engagement. The new Radius SDK unlocks fresh possibilities for digital identity, payment authentication, and proximity-driven marketing. It helps brands capture and act on their customers’ most important micro-moments by providing a seamless, hardware-agnostic way to detect presence, verify identity, and transfer data securely through ultrasonic technology.

Feature Overview

The release introduces:
  • ToneLock™: Three flexible options for payload security:
    • Custom-value provides app developers with full control over which devices can receive data
    • Account-based offers LISNR managed protection for all devices within your organization
    • Time-based guarantees timely access through automated expiration windows
  • AES-256 Encryption: End-to-end encrypted data payloads
  • Zone 266: The perfect combo of range and speed for 1:1 or 1:many transactions
All of this builds upon the existing core functionality that sets LISNR apart:
  • Versatile Tone Profiles for Any Use Case: Zone or Point tones optimized for distance, throughput, or movement
  • Callback Controls. Complete control over app logic for triggering engagements on tone detection
  • Multichannel Transceiving. Simultaneous 2-way data exchange on up to three channels
“This release marks a turning point for LISNR and our partners,” said Eric Allen, CEO of LISNR. “Ultrasonic technology is capable of far more than simply transmitting data—it’s about connecting merchants to customers, securely and in the moment, powering end-to-end engagements on and offline.”

Seamless Engagement, Multiplied

Radius 3.1 transforms ultrasonic tech from a behind-the-scenes protocol to a customer-facing solution for meaningful, frictionless engagement across mobility, retail, digital wallets, rewards, digital identity, events, hospitality, healthcare, and beyond. Visit the LISNR website to learn more about the Radius SDK.

ABOUT LISNR®

Today’s customer expects seamless, secure, and context-aware interactions—anytime, anywhere. LISNR® helps brands deliver on that expectation by powering proximity engagement that works without dependence on hardware, connectivity, or QR codes. With millions of transmissions in over 100 countries, LISNR’s ultrasonic SDK (Radius®) and gamified consumer engagement platform (Quest) allow businesses to recognize presence, personalize experiences, and process transactions in real-time. From mobility and retail to fintech and hospitality, LISNR bridges the gap between digital and physical with proximity-first experiences that drive loyalty, revenue, and trust. For more information, visit LISNR.com.

Radius®

Turn proximity into possibility.

Enables real-time proximity detection and secure access using just speakers and microphones. Integrating the Radius SDK into your app enables seamless interactions in any environment without relying on internet connectivity, Bluetooth, NFC, or QR codes.

See how Radius works →