The dataset viewer is not available for this split.
Error code: StreamingRowsError
Exception: CastError
Message: Couldn't cast
domain: string
tld: string
rank: int64
mode: string
outcome: string
reason: string
first_status: int64
final_status: int64
final_url: string
scheme: string
hops: int64
parked: bool
park_vendor: string
run_id: string
probed_at: timestamp[s]
chunks: list<item: struct<file: string, arm: string, rows: int64, rank_min: int64, rank_max: int64, bytes: i (... 22 chars omitted)
child 0, item: struct<file: string, arm: string, rows: int64, rank_min: int64, rank_max: int64, bytes: int64, sha25 (... 10 chars omitted)
child 0, file: string
child 1, arm: string
child 2, rows: int64
child 3, rank_min: int64
child 4, rank_max: int64
child 5, bytes: int64
child 6, sha256: string
span: int64
codec: string
to
{'run_id': Value('string'), 'codec': Value('string'), 'span': Value('int64'), 'chunks': List({'file': Value('string'), 'arm': Value('string'), 'rows': Value('int64'), 'rank_min': Value('int64'), 'rank_max': Value('int64'), 'bytes': Value('int64'), 'sha256': Value('string')})}
because column names don't match
Traceback: Traceback (most recent call last):
File "/src/services/worker/src/worker/utils.py", line 149, in get_rows_or_raise
return get_rows(
dataset=dataset,
...<4 lines>...
column_names=column_names,
)
File "/src/libs/libcommon/src/libcommon/utils.py", line 272, in decorator
return func(*args, **kwargs)
File "/src/services/worker/src/worker/utils.py", line 129, in get_rows
rows_plus_one = list(itertools.islice(safe_iter(ds, dataset=dataset), rows_max_number + 1))
File "/src/services/worker/src/worker/utils.py", line 489, in safe_iter
yield from ds.decode(False) if ds.features else ds
File "/usr/local/lib/python3.14/site-packages/datasets/iterable_dataset.py", line 2818, in __iter__
for key, example in ex_iterable:
^^^^^^^^^^^
File "/usr/local/lib/python3.14/site-packages/datasets/iterable_dataset.py", line 2355, in __iter__
for key, pa_table in self._iter_arrow():
~~~~~~~~~~~~~~~~^^
File "/usr/local/lib/python3.14/site-packages/datasets/iterable_dataset.py", line 2380, in _iter_arrow
for key, pa_table in self.ex_iterable._iter_arrow():
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
File "/usr/local/lib/python3.14/site-packages/datasets/iterable_dataset.py", line 536, in _iter_arrow
for key, pa_table in iterator:
^^^^^^^^
File "/usr/local/lib/python3.14/site-packages/datasets/iterable_dataset.py", line 419, in _iter_arrow
for key, pa_table in self.generate_tables_fn(**gen_kwags):
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
File "/usr/local/lib/python3.14/site-packages/datasets/packaged_modules/json/json.py", line 343, in _generate_tables
self._cast_table(pa_table, json_field_paths=json_field_paths),
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.14/site-packages/datasets/packaged_modules/json/json.py", line 132, in _cast_table
pa_table = table_cast(pa_table, self.info.features.arrow_schema)
File "/usr/local/lib/python3.14/site-packages/datasets/table.py", line 2369, in table_cast
return cast_table_to_schema(table, schema)
File "/usr/local/lib/python3.14/site-packages/datasets/table.py", line 2297, in cast_table_to_schema
raise CastError(
...<3 lines>...
)
datasets.table.CastError: Couldn't cast
domain: string
tld: string
rank: int64
mode: string
outcome: string
reason: string
first_status: int64
final_status: int64
final_url: string
scheme: string
hops: int64
parked: bool
park_vendor: string
run_id: string
probed_at: timestamp[s]
chunks: list<item: struct<file: string, arm: string, rows: int64, rank_min: int64, rank_max: int64, bytes: i (... 22 chars omitted)
child 0, item: struct<file: string, arm: string, rows: int64, rank_min: int64, rank_max: int64, bytes: int64, sha25 (... 10 chars omitted)
child 0, file: string
child 1, arm: string
child 2, rows: int64
child 3, rank_min: int64
child 4, rank_max: int64
child 5, bytes: int64
child 6, sha256: string
span: int64
codec: string
to
{'run_id': Value('string'), 'codec': Value('string'), 'span': Value('int64'), 'chunks': List({'file': Value('string'), 'arm': Value('string'), 'rows': Value('int64'), 'rank_min': Value('int64'), 'rank_max': Value('int64'), 'bytes': Value('int64'), 'sha256': Value('string')})}
because column names don't matchNeed help to make the dataset viewer work? Make sure to review how to configure the dataset viewer, and open a discussion for direct support.
Dead-Web Index — data
A reachability census of the most popular domains on the web. Every domain in the DomCop top-10M popularity list (this release: the full top 10 million) is probed and labelled alive / redirect / blocked / dead — once by an honest polite bot and once by a browser-like reachability client.
It is the dataset behind the Crawlora Dead-Web Index explorer.
What "dead" means
A domain is dead only if it is genuinely unreachable — no DNS resolution, a
refused/reset connection, or nothing accepting a TCP connection. A server that answers
any HTTP status (including 404, 5xx, or a Cloudflare 522) or merely accepts a TCP
connection is alive or blocked, not dead: the host is up, it just may not serve a
homepage or may refuse a bot. Many entries in a popularity list are asset/CDN/API hosts
(e.g. static.cloudflareinsights.com, fonts.googleapis.com) that 404 or tarpit a bare
GET / yet are very much alive.
- alive — a usable HTTP response (2xx, or a 4xx/5xx the server answered).
- redirect — ended on an unresolved redirect.
- blocked — host up but would not serve us: anti-bot / auth / rate-limit, or it accepts a TCP connection yet will not complete HTTP (tarpit/timeout, strict TLS).
- dead — no DNS, connection refused/reset, or nothing listening.
The two modes are the point: a polite plain-HTTP bot vs a reachability client with a real Chrome TLS/JA3 fingerprint. The gap — a domain dead/blocked to the bot but alive to the browser — is the slice of the web that is reachable with better tooling.
Files
The full per-arm data ships as release assets on the
latest release, split into
10 chunks per arm partitioned by DomCop rank (1,000,000 domains each) and compressed with
zstd. Every chunk is a self-contained 20 MB) — independently decodable, so you
can grab just the popularity band you need, resume a download, or fetch in parallel. The repo
carries a small preview, the run-level aggregates, and a checksummed manifest..jsonl.zst (
| file | rows | where | description |
|---|---|---|---|
polite.part-01.jsonl.zst … part-10 |
9,992,781 total | release assets | polite arm, 10 rank-partitioned chunks (part-01 = ranks 1–1,000,000 … part-10 = 9,000,001–10,000,000) |
reachability.part-01.jsonl.zst … part-10 |
9,997,315 total | release assets | reachability (browser) arm, same 10-chunk rank partition |
data/manifest.json |
— | in repo | per-chunk rows, rank range, byte size, and sha256 |
data/sample.jsonl |
1,000 | in repo | uncompressed preview (both arms) |
data/summary.json |
— | in repo | run-level aggregates (outcome split, by-reason, by-TLD) |
Getting the data
base=https://github.com/Crawlora-org/dead-web-index-data/releases/download/v1.0.0
# grab one arm's 10 chunks, then decode + concatenate into a single JSONL stream:
for i in $(seq -w 1 10); do curl -fL -O "$base/polite.part-$i.jsonl.zst"; done
zstd -dc polite.part-*.jsonl.zst > polite.jsonl # needs `zstd` (apt/brew install zstd)
zstd-compressed JSONL is read directly by DuckDB (read_json_auto('polite.part-*.jsonl.zst'))
and Polars; pandas needs the zstandard package (or just decode with zstd -d first). Verify
each download against the sha256 in data/manifest.json.
Each line is one JSON record:
{"domain":"example.com","tld":"com","rank":12345,"mode":"polite","outcome":"alive","reason":"ok","first_status":200,"final_status":200,"final_url":"https://example.com/","scheme":"https","hops":0,"parked":false,"run_id":"top10m-20260615","probed_at":"2026-06-15T..."}
| field | meaning |
|---|---|
domain |
the probed host |
tld |
last dot-label (coarse TLD) |
rank |
DomCop popularity rank |
mode |
polite or reachability |
outcome |
alive / redirect / blocked / dead |
reason |
finer reason (ok, dns_failed, timeout, not_found, forbidden, rate_limited, server_error, tls_error, connection_refused, …) |
first_status |
HTTP status of the first hop (0 if none) |
final_status |
HTTP status after redirects (0 if no response) |
final_url |
URL of the final response |
scheme |
https or http |
hops |
redirects followed |
parked / park_vendor |
parked/for-sale domain + vendor |
run_id |
scan run (this release: top10m-20260615) |
probed_at |
RFC3339 timestamp |
Method (brief)
HTTPS-first with HTTP fallback; cross-resolver DNS retry (8 public resolvers); redirects
followed (max 10); a retry on transient/timeout failures with an escalating deadline; a
raw TCP-connect check to separate "up but unresponsive" (blocked) from "gone" (dead);
parking-page detection. Homepage-level, from a datacenter vantage — a lower bound on
"alive" (deep pages and residential vantages reach more). The classification logic — DNS /
TCP / HTTP probing and the alive / redirect / blocked / dead rules — is open-sourced as a CLI
you can run on your own domains:
crawlora-deadweb
(go install github.com/Crawlora-org/crawlora-deadweb@latest).
This release
- run_id:
top10m-20260615· the full top 10,000,000 domains (DomCop), June 2026 - polite: 14.1% dead · 8.9% blocked · 76.6% alive · 0.3% redirect (9,992,781 domains)
- reachability: 14.1% dead · 8.2% blocked · 77.5% alive · 0.2% redirect (9,997,315 domains)
- Genuinely-dead (14.1%) is identical across both arms — no-DNS / no-connect does not depend on the client fingerprint. The browser-fingerprint arm clears more anti-bot walls, so its blocked rate is lower (8.9% → 8.2%): a real Chrome TLS/JA3 fingerprint reaches ~72,000 sites the polite bot is shut out of.
How to cite
This repository ships a CITATION.cff, so GitHub shows a “Cite this
repository” button that generates BibTeX/APA for you. Plain text:
Crawlora (2026). Crawlora Dead-Web Index: a reachability census of the top 10 million domains (v1.0.0) [Data set]. https://github.com/Crawlora-org/dead-web-index-data
Data collection & ethics
- Public infrastructure only. Each record is the result of an unauthenticated HTTP
GET /(plus DNS/TCP checks) to a domain's public homepage — the same request any browser makes. No authentication was bypassed, no login-only orrobots.txt-disallowed paths were fetched, and no page content is republished. The dataset records only the reachability state of a public endpoint. - No personal data. Records contain domain names and their observed HTTP/DNS status — no WHOIS registrant data, no emails, no personal identifiers. Domain names in a popularity ranking are public records of (overwhelmingly) organisations, not individuals.
- Point-in-time. This is a single snapshot (see
run_id); a domain dead today may resolve tomorrow and vice-versa. Treat it as a census, not a live status feed. - A lower bound on “alive.” Probing is homepage-level from a datacenter vantage. Deep
pages, residential vantages, and per-geo content reach more than a bare
GET /does, so the true “alive” share is somewhat higher than reported.
License
Data is licensed CC BY 4.0 — free to use, share and adapt with attribution to
Crawlora (https://crawlora.net). See LICENSE.
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