Cloud-based AI services from OpenAI, Anthropic, xAI and Google all suffered significant service interruptions within the same few-hour window on Thursday morning, an overlap that is highly unusual since these major frontier models rarely go down simultaneously. The near-concurrent failures briefly degraded access to ChatGPT, Claude, Grok and Gemini, drawing attention to how much users and businesses now rely on multiple AI providers whose infrastructure can apparently be strained at the same time.

Anthropic reported a partial outage affecting Claude Mythos 5.1, Claude Fable 5.1 and Claude Opus 5 from 9:23am (all times Eastern), resolving it by 12:16pm, with a separate brief issue hitting Claude Sonnet 5 just after noon. OpenAI logged elevated errors across ChatGPT and Codex from 10:43am, marking the issue resolved by 12:55pm, while xAI's Grok displayed user-facing error messages, with DownDetector reports spiking from under 10 to 1,365 within 45 minutes. Google did not publicly acknowledge problems with Gemini, but DownDetector reports rose sharply and monitoring service StatusGator recorded a likely outage between 10:45am and 11:15am; major infrastructure providers AWS, Azure and Cloudflare reported no major issues, though Claude and ChatGPT both cite over 99% uptime in the past 90 days.