Outage recap · Anthropic

Claude outage — October 27, 2026

On October 27, 2026, Claude had 3 reported incidents on Anthropic's official status page. Below is what was reported — impact, timing, and the AI services the same upstream outage could affect.

Elevated errors for Claude Sonnet 5.5

major
Started
Oct 27, 5:14 AM EDT
Resolved
Oct 27, 5:56 AM EDT
Duration
42 min

Anthropic's updates (3)

  1. investigating · Oct 27, 5:14 AM EDT

    We are investigating elevated errors on requests to Claude Sonnet 5.5. We will provide an update as soon as possible.

  2. monitoring · Oct 27, 5:38 AM EDT

    A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.

  3. resolved · Oct 27, 5:56 AM EDT

    The issue affecting Claude services has been resolved.

What our checks recorded

We checked Claude 9 times from Anthropic's start time to its resolution, once every five minutes. Every one of them reached Claude's site, so this incident did not show up as a failed page load. Our check loads the public site; it cannot see an API error or a broken feature. Median response time was 212 ms, against 270 ms over the 24 hours before. Anthropic posted the incident at Oct 27, 5:14 AM EDT.

Updates are Anthropic's own words from its status page (status: resolved); we never add an inferred cause. The vendor's incident page ↗

Elevated errors for Claude Sonnet 5.5

major
Started
Oct 27, 11:09 AM EDT
Resolved
Oct 27, 11:50 AM EDT
Duration
41 min

Anthropic's updates (2)

  1. identified · Oct 27, 11:09 AM EDT

    We are investigating elevated errors on requests to Claude Sonnet 5.5. We will provide an update as soon as possible.

  2. resolved · Oct 27, 11:50 AM EDT

    The issue affecting claude.ai, the Claude API, Claude Code, and Claude Cowork has been resolved. Impact occurred from 07:42 PT / 14:42 UTC to 08:17 PT / 15:17 UTC.

What our checks recorded

We checked Claude 8 times from Anthropic's start time to its resolution, once every five minutes. Every one of them reached Claude's site, so this incident did not show up as a failed page load. Our check loads the public site; it cannot see an API error or a broken feature. Median response time was 256 ms, against 259 ms over the 24 hours before. Anthropic posted the incident at Oct 27, 11:09 AM EDT.

Updates are Anthropic's own words from its status page (status: resolved); we never add an inferred cause. The vendor's incident page ↗

Elevated errors affecting the Gmail connector

minor
Started
Oct 27, 11:59 PM EDT
Resolved
Oct 28, 1:48 AM EDT
Duration
1h 49m

Anthropic's updates (3)

  1. investigating · Oct 27, 11:59 PM EDT

    We are investigating elevated errors when searching and reading email with the Gmail connector. This issue does not affect other connectors. We will provide an update as soon as possible.

  2. investigating · Oct 28, 12:00 AM EDT

    We are investigating elevated errors when searching and reading email with the Gmail connector. This issue does not affect other connectors.

  3. resolved · Oct 28, 1:48 AM EDT

    The issue affecting the Gmail connector on claude.ai, Claude Code, and Claude Cowork has been resolved. Impact occurred from 16:00 PT / 23:00 UTC on October 27 to 22:29 PT on October 27 / 05:29 UTC on October 28.

What our checks recorded

We checked Claude 22 times from Anthropic's start time to its resolution, once every five minutes. Every one of them reached Claude's site, so this incident did not show up as a failed page load. Our check loads the public site; it cannot see an API error or a broken feature. Median response time was 270 ms, against 276 ms over the 24 hours before. Anthropic posted the incident at Oct 27, 11:59 PM EDT.

Updates are Anthropic's own words from its status page (status: resolved); we never add an inferred cause. The vendor's incident page ↗

The AI cascade

Claude depends on Anthropic. When that upstream has an incident, it doesn't hit Claude alone — these AI tools share the dependency and can degrade at the same time:

CursorWindsurfGitHub CopilotTabnineSourcegraph CodyClineRoo CodeContinue
Is Claude down right now? →Claude status history →

AIDownCheck is not affiliated with Anthropic. This recap summarizes incidents published on Anthropic's official status page.