503RADARINCIDENT ARCHIVEMETHODOLOGY
RESOLVED

Anthropic outage — August 17, 2026

Degraded performance for Claude Opus 5, Claude Sonnet 5

Anthropic’s Claude.ai was disrupted for 5h 30m on August 17, 2026. 503Radar’s sensors raised the first signal at 10:24 UTC, 3h 43m before the official status page acknowledged impact.

Key facts

DetectedAugust 17, 2026 · 10:24 UTC
Confirmed14:08 UTC · lead time 3h 43m
Resolved15:54 UTC
Duration5h 30m
ServiceClaude.ai
Official recordhttps://stspg.io/dw9p8s0wg6hh

Timeline

  1. 10:24Z

    Detected · Signal

    1 crowd signal for Claude.ai on ANTHROPIC crossed the signal threshold.
  2. 14:08Z

    Confirmed · Official

    An official ANTHROPIC status-page notice corroborated the event — 3h 43m after detection.
  3. 15:54Z

    Resolved

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

How this was detected

1 independent evidence class for claude-ai on ANTHROPIC. 1 crowd report across bluesky (single platform — not corroborating), z=-0.5σ vs the cell baseline. Official notice confirms it, 3h 43m after the crowd.