ChatGPT, Claude, and Grok all experienced service problems during overlapping periods on Thursday, leaving users of three major AI platforms unable to rely on their usual assistants. The timing was similar, but there is no evidence so far that the incidents shared a cause.
OpenAI reported elevated errors across ChatGPT and Codex beginning around 11 a.m. Eastern time. The disruption affected conversations as well as logins, file uploads, voice mode, search, deep research, and image generation. The company said it applied a mitigation and was monitoring recovery, although degraded performance continued for some tools.
Anthropic attributed its partial outage to an infrastructure issue. Claude, Claude Code, and the Claude API were affected before the company said service was restored at about 12:15 p.m. Eastern. Grok had begun showing problems earlier, around 9:30 a.m., across the web and its Android and iOS apps. Users on X received messages saying the model was overloaded while xAI worked to restore service.
Simultaneous failures across independent providers highlight the operational risk of building a workflow around one hosted assistant, even when the underlying models differ. For businesses that treat these services as production dependencies, the incident is a reminder to monitor provider status and plan fallbacks rather than assuming a popular AI API will always be available.