Demod: SDR Receiver

Demod turns your iPhone into a software-defined radio receiver. Connect to an SDR server on your own network or anywhere on the internet and explore the airwaves — from shortwave broadcasts and ham radio to aircraft, marine, and FM.

Demod is a client for the most common SDR servers:
• rtl_tcp — for RTL-SDR dongles
• SpyServer — for Airspy and RTL-SDR
• KiwiSDR — HF web receivers
• OpenWebRX — web SDRs (HF, VHF and UHF)

There's no hardware to plug into your phone. Point Demod at a server you run (a Raspberry Pi, PC, or Mac with an SDR dongle), or browse hundreds of public servers around the world and start listening in seconds.

FEATURES
• Real-time waterfall and spectrum display — Metal-accelerated and smooth
• Pinch to zoom, drag to tune, two-finger pan
• AM, NFM, WFM, USB, LSB, and CW demodulation
• Decode CW (Morse), RTTY, PSK31, and FT8 on-screen (beta)
• Maritime decoders: NAVTEX text broadcasts, DSC calls on MF/HF and VHF channel 70 (beta), and WeatherFAX charts saved as images — receive-only, not for navigation or safety
• Time-Shift: pause and rewind live radio, DVR-style
• Record what you hear — with a pre-roll of the moment you tapped
• Live Text: on-device transcription of what you're listening to, with on-device translation of the captions (iOS 18+) and a full-screen transcript reader
• Identify: one-tap "what is this signal?" — measures the signal on-device, matches it against a built-in band plan, and suggests the right mode (works with Siri: "ask Demod what this signal is")
• Scanner: scan your memories, a band range, or let Smart scan find active signals across the captured spectrum
• Spectral noise reduction, noise blanker, and mains-hum notch
• Browse public KiwiSDR, OpenWebRX, and SpyServer receivers worldwide — list or map view
• Save and recall favorite frequencies — import and export as CSV
• Direct-sampling and upconverter support for HF
• AirPlay / HomePod button on the main screen, Lock Screen playback controls, and a sleep timer that fades out and stops
• Adjustable bandwidth, gain (auto or manual), squelch, and display layouts

PRIVACY
Demod collects no data. No accounts, no tracking, no ads. Recording, transcription, translation, and signal identification all run entirely on your device — audio and text never leave it. Your settings, recordings, transcripts, decoder logs, and fax charts stay on your device, under your control.

Built for radio hobbyists, shortwave listeners, scanner enthusiasts, and ham operators who want a fast, native receiver in their pocket.

Note: Demod is a receiver client and requires an SDR server to connect to. You can use a server you run yourself or one of the many free public servers listed in the app.