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)
• 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 output and Lock Screen playback controls
• 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, and transcripts stay 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.

Demod in the car, a smarter Seek, and a squelch that works everywhere:

• CarPlay — listen to Demod on your car's screen. Pick a recent server or a saved station, see the band, station and country on the Now Playing screen, and use the steering-wheel buttons. Radio now plays across the car's music speakers instead of the voice speaker.
• Seek — next/previous (in the app, in the car and on your headphones) now jumps to the next real signal for the mode you're in and stops there: the next AM station, the next SSB voice, the next CW signal. It stays inside the band you're tuned to and searches the whole receiver when you're between bands.
• Siri and Shortcuts — "Tune Demod", "Play WWV in Demod" (any saved station), "Listen to (a favorite receiver) in Demod", or "Ask Demod what this signal is".
• Identify, upgraded on iOS 27 — Demod reads the waterfall itself to help work out what an unknown signal is.
• Squelch now works on KiwiSDR and OpenWebRX, and uses the same dB reading as the signal meter, so it's easy to set: put it just above the noise (thank you to our reviewer for the feedback!)
• Band plans for your country, chosen automatically from the receiver's location and editable in the app (another great feedback item!)
• More reliable listening on the move — Demod reconnects on its own after a dead zone and brings the audio back with it, and pauses for phone calls and Siri then picks up again.
• FT8 no longer misses the start of transmissions on some receivers.
• "Keep screen on while listening" option, and Recent Servers now list newest first.