OpenAI, Anthropic, and xAI Report Major AI Service Disruptions

Cloud-based AI services from OpenAI, Anthropic, and xAI experienced overlapping outages and performance issues for several hours Thursday morning. The disruptions affected popular AI platforms, including Claude, ChatGPT, Codex, and Grok.

Anthropic first reported a “partial outage” at 9:23 a.m. ET involving increased errors for requests sent to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. The company said it identified the cause roughly 15 minutes later, deployed a fix, and resolved the incident by 12:16 p.m. ET.

A second Anthropic incident report noted a brief increase in errors affecting requests to Claude Sonnet 5 shortly after noon.

OpenAI reported degraded performance beginning at approximately 10:43 a.m. ET. The company attributed the issue to increased errors across ChatGPT and Codex. OpenAI said it implemented mitigations a little over 30 minutes later and marked the incident as resolved at 12:55 p.m. ET.

xAI’s Grok also experienced an apparent service disruption. Users were shown an error message stating that the model was “experiencing an issue” and that the company was “working to restore service as soon as possible.”

User reports submitted to DownDetector indicated a sharp increase in Grok outage reports. Reports rose from fewer than 10 shortly before 9 a.m. ET to 1,365 by 9:45 a.m., before falling to 273 at the time of writing.

The simultaneous incidents highlight the growing dependence on centralized cloud infrastructure powering today’s leading generative AI services. Although the reported problems were resolved or began to subside within a few hours, temporary outages can affect millions of users and businesses that rely on AI tools for productivity, software development, and customer support.