OpenAI's ChatGPT experienced a significant outage on June 4, 2024, affecting many users worldwide. The service was reported as down for over five hours, starting around 12:21 am PDT. OpenAI confirmed the issue and stated that they were investigating the cause. Other AI services, including Claude, Perplexity, and Gemini, also experienced simultaneous outages, raising concerns about a broader issue affecting multiple platforms. Some users reported momentarily seeing GPT4.5 during the outage. The outage, which occurred for the second time that day, caused disruptions for users relying on these AI tools for various tasks. By the afternoon, OpenAI reported that the issue had been resolved, and ChatGPT was back online.