your body casts a shadow in wifi · network info api · rtt probe · stand still calibrate then walk · perturbation timeline · runs locally
your body is opaque to wifi. as you move between this device and your router your body casts a shadow in the signal. this tool shows that shadow.
this tool measures what your browser exposes about your wifi connection. browsers deliberately limit access to raw signal strength for privacy reasons. what you see here is an approximation of what professional wifi sensing systems measure with full radio hardware access. the phenomenon is real. the browser measurement is limited. results vary by device, browser, and router proximity.
on this browser, the network information api is not available— only the rtt probe channel will work. chrome on android typically exposes both.