Claude has massively stopped working: Anthropic confirmed login and Claude Code outage

Claude users worldwide faced authentication errors and complete service unavailability. Anthropic confirmed the problem and began an investigation.

A massive Claude outage occurred on the evening of August 16. When trying to access the service, users receive messages "Claude is temporarily unavailable" and "Authentication service was unavailable", and repeated login attempts do not resolve the issue.

Anthropic officially acknowledged the incident at 21:58 UTC. The company reported that it is investigating issues with user authentication on claude.ai, Claude Code, and Claude Cowork. At the time of publication, the cause of the outage has not been identified, and the timeline for full recovery is unknown.

On the Anthropic status page, claude.ai, Claude Code, and Claude Cowork are marked as services with a major outage. However, Claude API and the developer console were displayed as operating normally at the last check.

The scale of the problem is also visible from Downdetector data. The number of complaints about Claude sharply increased from almost zero to several thousand in a short period of time. At its peak, the graph approached the mark of 9 thousand problem reports.

Users primarily report being unable to log in to their accounts, open existing conversations, and resume work with Claude. The Claude Code outage is especially sensitive for developers and companies that use Anthropic's service in their daily work with software code.

This is not the first significant technical incident involving Claude in recent days. On August 14–15, Anthropic recorded separate outages of Claude API, Claude Code, and Claude Cowork, as well as an increased number of errors when accessing one of the Claude models.

Thus, the current incident occurred against the backdrop of a series of issues with Claude's infrastructure. Anthropic continues its investigation and has not disclosed the technical cause of the new outage.

Sources: Anthropic Status, Downdetector, StatusGator.