A single-file software-defined radio receiver that runs entirely in a Chromium-based browser via WebUSB, requiring no installation, no internet, and no admin rights—just an RTL-SDR stick, an antenna, and `index.html` on a USB drive. The project is designed for offline and remote use cases, such as field expeditions, emergency kits, and locked-down computers, supporting FM stereo with RDS, shortwave, airband, PMR446, and general coverage from 100 kHz to 1.766 MHz.
- Decodes weather fax, Morse code (auto speed detection), and RDS, with an "Identify" menu that optionally queries shortwave.live or a web search for the tuned frequency.
- Includes a Panorama feature that sweeps up to 10 MHz at once and stitches the slices together for a wideband view.
- Built using Jacobo Tarrío's `webrtlsdr` and `signals` libraries (from the original Google Radio Receiver Chrome app), bundled into one file with esbuild.
- The US National Weather Service proposed closing its five HF radiofax stations in late 2026.
- Demo mode is available without a stick by opening `index.html?demo`, which simulates stations including FM stereo with RDS, fading shortwave, SSB, Morse, and weather fax.
- Decodes weather fax, Morse code (auto speed detection), and RDS, with an "Identify" menu that optionally queries shortwave.live or a web search for the tuned frequency.
- Includes a Panorama feature that sweeps up to 10 MHz at once and stitches the slices together for a wideband view.
- Built using Jacobo Tarrío's `webrtlsdr` and `signals` libraries (from the original Google Radio Receiver Chrome app), bundled into one file with esbuild.
- The US National Weather Service proposed closing its five HF radiofax stations in late 2026.
- Demo mode is available without a stick by opening `index.html?demo`, which simulates stations including FM stereo with RDS, fading shortwave, SSB, Morse, and weather fax.
Richard Didd has released OFFgrid-SDR, a fully offline RTL-SDR receiver that runs in a single HTML file without requiring any installation or internet access. The program utilizes WebUSB in modern browsers to demodulate various signal types and display spectrum and waterfall data, while also including built-in decoders for RDS, weather fax, and Morse code. Its primary advantage is portability, allowing users to store the application on a USB drive and run it on almost any machine with a compatible browser.
- Windows users must install WinUSB drivers via Zadig
- Linux users must blacklist DVB-T drivers
- macOS and Chromebook require no additional setup
- Project documentation is available on the developer's Hackaday.io page
- Windows users must install WinUSB drivers via Zadig
- Linux users must blacklist DVB-T drivers
- macOS and Chromebook require no additional setup
- Project documentation is available on the developer's Hackaday.io page
