Four Major AI Models Experience Overlapping Downtime

A rare and significant set of overlapping service interruptions affected major cloud-based AI models operated by OpenAI, Anthropic, xAI, and Google on Thursday morning, impacting users for several hours. The incidents highlight the interconnectedness and potential fragility of the AI infrastructure powering many popular services.

Anthropic was the first to report issues, noting a "partial outage" at 9:23 am Eastern Time. This outage was linked to "elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5." The company identified the cause approximately 15 minutes later and deployed a fix, resolving the primary issue by 12:16 pm. A subsequent, brief incident report indicated "elevated errors on requests to Claude Sonnet 5" shortly after noon, suggesting a potential ripple effect or a separate, minor issue. Anthropic's Claude family of models are known for their advanced reasoning and conversational abilities, often used in enterprise applications and research.

Concurrently, OpenAI reported "elevated errors across ChatGPT and Codex" starting around 10:43 am, leading to "degraded performance." ChatGPT is OpenAI's flagship conversational AI, while Codex is a model trained on code, used for code generation and understanding. OpenAI implemented a mitigation strategy that began to take effect over 30 minutes later, and the issue was officially marked as "resolved" by 12:55 pm. These services are widely used by individuals and developers for a broad range of tasks, from content creation to software development.

While the article does not detail the specific issues faced by xAI and Google, their inclusion in the report of overlapping downtime suggests that their AI services also experienced disruptions during the same timeframe. The simultaneous nature of these outages across multiple leading AI providers is unusual and points to potential common underlying infrastructure vulnerabilities or external factors affecting cloud services. The duration of these interruptions, ranging from under an hour to several hours for some services, underscores the critical reliance on these AI platforms for daily operations across various sectors, including business, research, and consumer applications. The resolution of these issues by midday indicates the rapid response capabilities of these major technology companies, though the event raises questions about the resilience of AI service delivery.