Claude AI down: Users report ‘authentication service unavailable’ error amid outage
Update: Claude AI is back up after a brief outage reported across the United States on Sunday evening.

Anthropic’s status page said, “The issue affecting claude.ai, platform.claude.com, the Claude API, Claude Code, and Claude Cowork has been resolved.”
Earlier, the company said, “A fix has been deployed for the issue affecting claude.ai, platform.claude.com, the Claude API, Claude Code, and Claude Cowork and we are monitoring for recovery.”
Anthropic has not said what caused the outage.
Also Read: We taught machines to generate answers. Now, they need to be checked and verified
Initial report: Claude is facing a widespread outage, with users reporting authentication errors and difficulty accessing the AI chatbot. Anthropic’s status page shows a service disruption affecting Claude services.
Downdetector reports
According to outage-tracking site Downdetector, reports of problems began rising around 6 p.m. EDT on Sunday.
Users in several parts of the US reported seeing an “authentication service unavailable” error when trying to access Claude.
By 6:15 p.m., Downdetector had received over 15,000 error reports.
One user wrote, “It’s been down about 15 minutes now, keep getting an authenticator error.”
Another added, “All claude is down, we are in the stone age now.”
A third user reported, “Claude is not working. I cant send messeges.”
Another wrote, “I am experiencing Claude service outage for at least last 15 minutes. I’m in Silicon Valley.”
One more user added, “At least it’s on a Sunday (Los Angeles time). Sorry for folks that this is hitting their work day.”
Also Read: Open-weight AI won’t crimp demand for picks and shovels
What Anthropic said
Anthropic initially acknowledged the problem on its status page, saying it was investigating an issue affecting users trying to authenticate to claude.ai, Claude Code, and Claude Cowork.
In a later update, the company said, “We are investigating reports of degraded performance affecting claude.ai, platform.claude.com, the Claude API, Claude Code, and Claude Cowork. We will provide an update as soon as possible.”