China cuts ties with the global internet for 60 minutes, world baffled — here’s what happened

On August 20, 2025, for about 60 minutes, China’s internet was disconnected from the global web, leaving experts and users confused. Activist group Great Firewall Report spotted the outage. They said it stopped all traffic to TCP port 443, which is the standard port for HTTPS websites.

The group wrote, “Between approximately 00:34 and 01:48 (Beijing Time, UTC+8), the Great Firewall of China exhibited anomalous behavior by unconditionally injecting forged TCP RST+ACK packets to disrupt all connections on TCP port 443”. This disruption meant Chinese netizens couldn’t reach most websites hosted outside China, which caused major inconvenience, as reported by The Register.

China internet outage

The outage also blocked other services using port 443, which is critical because many services, like Apple and Tesla, rely on this port to connect to servers outside China. China sometimes increases censorship during events it doesn’t want the public to know about, but The Register found no such event occurred during this outage.


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Great Firewall glitch

The Great Firewall Report noticed that the device causing the block did not match any known fingerprints of existing Great Firewall devices. The group suggested the incident could be caused by a new GFW device or a known device operating in a new or misconfigured way. Possible reasons include: China testing the ability to block port 443, which might be useful for them, or someone accidentally misconfiguring the system, according to the report by The Register.

The Great Firewall has glitches before, sometimes leaking information or leaving itself open to attacks. China’s overall censorship system is imperfect due to technical and bureaucratic errors. China is known to share the technology behind the Great Firewall with other nations. For example, Pakistan reportedly implemented its own version, and NetBlocks reported a big drop in Pakistan’s internet traffic a few hours before China’s outage.

Experts are still unsure why China blocked port 443 for an hour, and whether it was intentional testing or a technical mistake. The short disruption shows how critical port 443 is for global internet connections and how even a short outage can impact major companies and services worldwide. While the reason remains unclear, the world is now closely watching China’s internet operations, because even small disruptions can have wide global effects, as stated in the report by The Register.

FAQs

Q1. Why did China’s internet go down for 60 minutes?
China’s Great Firewall temporarily blocked port 443, stopping access to most websites outside China, but the exact reason is unclear.

Q2. Which services were affected by China’s internet outage?
Websites hosted outside China and services like Apple and Tesla that use port 443 were disrupted during the outage.