DeepSeek hit by longest outage since launch

China's leading AI chatbot DeepSeek experienced its longest outage ever on Sunday evening. The service was down for several hours, affecting users across China.

According to Downdetector, problems began around 9:35 PM local time on Sunday. DeepSeek confirmed the fault on its status page and initially marked it as resolved within two hours, but further updates showed continued performance issues.

A final fix was deployed Monday morning at 9:13 AM. The company has not shared details about the root cause.

The timing is notable. The outage comes amid growing speculation about a major update from DeepSeek. The platform has maintained an impressive uptime record since launching its R1 model in January 2025 and is considered a key player in China's AI space.

For enterprises evaluating Chinese AI services, this is a reminder that even the most promising platforms can experience significant downtime without warning.