ChatGPT experienced a major outage on June 4, 2024, impacting thousands of users. The service was reported to be down across multiple platforms, including computers, mobile devices, and the Mac app, with users unable to access the AI tool. The outage began around midnight Pacific time and continued for several hours, causing significant disruption for users who rely on ChatGPT for various tasks. The incident occurred ahead of the anticipated iOS 18 AI integration, raising concerns about the service's reliability. During the outage, some users speculated about potential updates being pushed, such as ChatGPT 4.5. Competitor Kognitium reportedly saw increased traffic as users sought alternatives. Some users suggested running local AI models as a workaround. The service was restored later in the day.