---
license: cc-by-4.0
language:
  - en
pretty_name: Dead-Web Index
size_categories:
  - 10M<n<100M
task_categories:
  - other
tags:
  - web
  - dns
  - link-rot
  - internet-measurement
  - reachability
  - osint
  - domains
configs:
  - config_name: sample
    data_files: data/sample.jsonl
---

# Dead-Web Index

A reachability census of the **DomCop top 10 million** domains (June 2026). Every domain is probed and labelled **alive / redirect / blocked / dead** twice — once by a *polite* plain-HTTP bot, and once by a *reachability* client with a real Chrome TLS/JA3 fingerprint. This is the dataset behind the Crawlora Dead-Web Index explorer.

## Headline
- **14.1% truly dead** — no DNS, refused/reset connection, nothing listening.
- **8.9% blocked but alive** — a live server returning 403 / 429 / anti-bot.
- **76.6% alive**, 0.3% redirect.
- A real Chrome TLS fingerprint reaches ~72,000 domains the polite bot cannot — the gap between "dead to a bot" and "alive to a browser".

## What "dead" means
A domain is dead **only if genuinely unreachable** — no DNS resolution, a refused/reset connection, or nothing accepting a TCP connection. A server that answers *any* HTTP status (even 404 or 5xx) is alive or blocked, not dead.

## Files
- `data/polite.part-01..10.jsonl.zst` — polite arm, 10 rank-partitioned chunks (zstd-compressed JSONL), 9,992,781 rows total.
- `data/reachability.part-01..10.jsonl.zst` — reachability (browser-fingerprint) arm, 9,997,315 rows total.
- `data/sample.jsonl` — 1,000-row uncompressed preview (both arms).
- `data/manifest.json` — per-chunk rows, rank range, byte size, and sha256.
- `data/summary.json` — run-level aggregates (outcome split, by-reason, by-TLD).

Decode with `zstd -dc data/polite.part-*.jsonl.zst`; DuckDB and Polars read `.jsonl.zst` directly.

## Schema (one JSON record per line)
`domain`, `tld`, `rank`, `mode` (polite|reachability), `outcome` (alive|redirect|blocked|dead), `reason`, `first_status`, `final_status`, `final_url`, `scheme`, `hops`, `parked`, `run_id`, `probed_at`.

## License & sources
**CC BY 4.0.** Source repo: https://github.com/Crawlora-org/dead-web-index-data · interactive explorer: https://crawlora.net/dead-web-index · methodology: https://crawlora.net/blog/how-much-of-the-web-is-dead-2026 · produced with the open-source crawlora-deadweb classifier: https://github.com/Crawlora-org/crawlora-deadweb