{
  "id": "palimpsest-news:ooni-gfw",
  "slug": "ooni-great-firewall-index",
  "url": "https://palimpsest.info/news/ooni-great-firewall-index/",
  "signal_id": "ooni-gfw",
  "headline": "OONI's China anomaly index is 58.3% across 272,935 completed measurements",
  "dek": "The index aggregates volunteer-probe observations across network test families inside China.",
  "section": "network",
  "order": 1,
  "type": "measurement",
  "priority": "lead",
  "status": "live",
  "published_at": "2026-08-24T02:00:59Z",
  "modified_at": "2026-08-24T02:00:59Z",
  "claim_fingerprint": "sha256:44944031bae0d9d60f823f2820837339c9e9bf672928879a929549e059409208",
  "metric": {
    "label": "GFW anomaly index",
    "value": 58.3,
    "unit": "percent",
    "denominator": {
      "label": "completed measurements",
      "value": 272935
    }
  },
  "claims": [
    {
      "type": "finding",
      "statement": "The current OONI aggregate reports a 58.3% anomaly index across 272,935 completed China measurements."
    }
  ],
  "evidence": {
    "url": "https://palimpsest.info/readings/ooni-gfw-latest.json",
    "input": {
      "filename": "ooni-gfw-latest.json",
      "sha256": "90accfb51b97976a774e922f9874ab3af2d4fe9a81b934354dfa714981bf1009",
      "bytes": 7989
    },
    "source_timestamp": "2026-08-24T02:00:59Z"
  },
  "method": {
    "summary": "side-channel: we ingest OONI's already-aggregated open data; gfw_index is anomalous completed measurements divided by all completed measurements; we never probe a censored resource ourselves (vantage-insensitive)",
    "version": 2
  },
  "limitations": [
    "Volunteer-probe coverage is uneven across place, network and test family; anomalies are not all attributable to censorship."
  ],
  "related_signal_ids": [
    "in-path-interference",
    "censored-planet",
    "inside-view",
    "vantage-fusion"
  ]
}