Main Online SDR Platforms

Hardware + software project that turns a BeagleBone into a web-accessible HF receiver covering roughly 10 kHz to 30 MHz. Multiple users can listen and tune independently at the same time.

Strengths: continuous HF coverage, good for shortwave broadcast, amateur HF, utilities, time signals, and TDoA experiments. Many have GPS timing.

Find them: rx.linkfanel.net map · kiwisdr.com/public · Receiverbook

The classic multi-user web SDR software written by Pieter-Tjerk de Boer, PA3FWM. Often used with SoftRock, RTL-SDR, SDRPlay or other hardware on specific bands or wider ranges.

Famous example: the University of Twente receiver in the Netherlands, which has been online for many years and can handle large numbers of simultaneous users.

Find them: websdr.org

Modern open-source web SDR server. Supports a wide range of hardware (RTL-SDR, SDRPlay, Airspy, LimeSDR, etc.) and can cover HF, VHF, UHF and sometimes higher. Often includes digital mode decoding (FT8, ADS-B, etc.).

Very common for VHF/UHF amateur, airband, marine, PMR and satellite (including QO-100) receivers.

Find them: Receiverbook · rx-tx.info

Projects such as RX-888 + UberSDR, Web-888 and similar wideband direct-sampling receivers are appearing more often. They offer high dynamic range and continuous coverage, and are increasingly listed on the curated “best SDR” pages (e.g. Skywave Linux).