503RADARINCIDENT ARCHIVEMETHODOLOGY
RESOLVED

Anthropic outage — September 1, 2026

Degraded performance on platform.claude.com and Claude for Microsoft Office 365

Anthropic’s Claude.ai was disrupted for 1h 19m on September 1, 2026.

Key facts

DetectedSeptember 1, 2026 · 17:05 UTC
Confirmed17:05 UTC
Resolved18:24 UTC
Duration1h 19m
ServiceClaude.ai
Official recordhttps://stspg.io/4rf459q4pjc3

Timeline

  1. 17:05Z

    Detected · Signal

    2 crowd signals for Claude.ai on ANTHROPIC crossed the signal threshold.
  2. 17:05Z

    Confirmed · Official

    An official ANTHROPIC status-page notice corroborated the event the same cycle.
  3. 18:24Z

    Resolved

    Signal volume fell back below the threshold; the event was closed.

Evidence

Official status feeddegraded (changed 17:05 UTC)
Anomaly score+0.61σ above this cell's own baseline
Engine confidence95%

Outage-related signals per hour over the live window, oldest → newest (peak 1).

How this was detected

1 independent evidence class for claude-ai on ANTHROPIC. 2 crowd reports across bluesky (single platform — not corroborating), z=+0.6σ vs the cell baseline. Official notice confirms it.