ChatGPT, Claude, and Grok experienced service disruptions Thursday morning, preventing some users from accessing the AI platforms or generating responses.

OpenAI, Anthropic, and xAI acknowledged problems affecting their services, though it is unclear if the incidents were connected.

On X, users said the outages had disrupted their work, leaving them without AI tools they used for writing, research, coding, and other daily tasks.

“Claude, Grok and ChatGPT. How can anyone get any work done?” chemist and science communicator Simon Maechling wrote on X.

“ChatGPT is down, and I am immediately 50 IQ points dumber,” AI tool developer Every CEO Dan Shipper joked.

OpenAI drew the most complaints, with reports on Downdetector peaking at approximately 38,000. Among users who identified a specific problem, 80% selected ChatGPT, 8% Codex, and 7% the app.

The company began investigating elevated errors affecting ChatGPT and Codex at 10:43 a.m. EST. OpenAI said it applied a mitigation at 11:17 a.m. and was monitoring the recovery.

“A routing error starting around 7:43 am PT on Thursday, September 3 made ChatGPT and Codex unavailable for some users across platforms,” an OpenAI spokesperson told Decrypt. “As of about 8:17 a.m. PT on Thursday, a solution was successfully implemented and is continuing to be monitored.”

Anthropic began investigating elevated error rates for Claude Sonnet 5 at 8:37 a.m. EST and marked the problem resolved 19 minutes later, according to its status page.

A second incident affecting several Claude models began at 9:26 a.m. EST. Anthropic said it identified the cause, deployed a fix, and ended the incident by 12:16 p.m. EST. It did not disclose the cause.

Claude complaints on Downdetector peaked near 1,400. Claude Chat accounted for 35% of categorized reports, followed by Claude Code at 34% and the app at 23%.

“Claude is fully back up after an infrastructure issue caused a partial outage across Claude.ai, Claude Code, Claude Cowork, and the Claude API earlier today. Service was restored at 16:16 UTC,” an Anthropic spokesperson told Decrypt.

Elon Musk’s xAI confirmed an outage affecting Grok’s web and mobile apps, its presence on X, and two U.S. API regions. At 9:30 a.m. EST, the company said it was investigating and working to restore service. Grok complaints peaked at roughly 1,400.

OpenAI, Anthropic, and xAI said the ChatGPT and Codex, Claude, and Grok outages were resolved by 12:55 p.m., 12:16 p.m., and 1:07 p.m. EST, respectively.

The outages on Thursday are the most recent in a history of AI chatbot interruptions.

ChatGPT has suffered a number of outages, including a December 2024 disruption that knocked the service offline shortly after its Apple Intelligence integration launched and a June 2025 global outage that lasted more than three hours and affected millions of users.

The outages also hit as competition among AI assistants continues to shift.

At last count, ChatGPT served more than 1 billion weekly active users, Claude had an estimated 300 million monthly active users, and Grok had approximately 117 million monthly active users as of March 2026.

Web-traffic estimates in June 2025 put ChatGPT’s share of the generative AI market near 80%. By August 2025, Gemini and Grok were gaining ground. Data published in May 2026 showed ChatGPT losing more traffic share to its rivals.