China's internet experienced a significant disruption on August 20, as access to most global websites was blocked for nearly an hour, impacting millions. The activist group Great Firewall Report identified that from 12:34 AM to 1:48 AM Beijing time, TCP port 443—critical for secure connections—was obstructed. This unexpected outage raises concerns over potential technical errors or an experimental test by the authorities, although no major events explained the disruption.