A WebSDR is a Software-Defined Radio receiver connected to the internet, allowing many listeners to listen and tune it simultaneously. SDR technology makes it possible that all listeners tune independently, and thus listen to different signals; this is in contrast to the many classical receivers that are already available via the internet.

More background information is available here. Questions and comments can be sent to PA3FWM, the author of the WebSDR software and maintainer of this site; but please check the frequently asked questions first.

WebSDR servers can register themselves automatically on this site, leading to the below list of currently active WebSDR servers.

Currently there are - servers active, with - users and - MHz of radio spectrum.

Filter band: and region: and mobile support and covering MHz.

Note: the locations on the map are only accurate to a few km, because they are derived from the QTH locators.