Four major AI models suffer rare overlapping downtime

On Thursday morning, OpenAI, Anthropic, xAI, and Google experienced simultaneous service disruptions affecting their cloud-based AI models. Anthropic reported elevated errors on Claude Mythos 5.1, Claude Fable 5.1, Claude Opus 5, and briefly on Claude Sonnet 5, resolving the issue by 12:16 pm after deploying a fix. OpenAI saw degraded performance on ChatGPT and Codex from 10:43 am, implementing a mitigation that cleared the errors by 12:55 pm.