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APRS Web Softmodem


APRS audio modem in the browser.
Encode and decode APRS packets using WebAssembly, Web Audio and your browser microphone.

APRS Web Softmodem is a browser-based APRS modem experiment. It runs the packet modem logic in WebAssembly, uses the Web Audio API for transmit and receive audio, and can display heard stations on a map.

Plain English: it turns your browser into a tiny APRS modem. No native app, no driver install, no soundcard configuration screen from 1998.

What it can do

  • Decode APRS audio from your microphone
  • Generate APRS transmit audio in the browser
  • Send plain APRS messages
  • Send APRS position packets
  • Run a loopback test without radio hardware
  • Show heard stations on a map
  • Run the modem core through WebAssembly

Try the demo

The demo is a standalone static web app and can be hosted from the same site.

Open APRS Web demo

Who is it for?

This project is aimed at radio amateurs, APRS experimenters, browser audio nerds and anyone curious about packet radio without installing a full desktop modem stack.

Project status

This is currently best described as an experiment / technical demo rather than a polished radio application.

Native tools, weird experiments, and practical performance work.