Everything CrawlCheck got wrong, in writing.
A published figure, page or decision that turns out to be wrong is corrected where it appears and recorded here with the date, what was wrong and what changed. Nothing is quietly edited: a dataset snapshot is superseded, never rewritten.
| Date | Area | Class | What was wrong | What changed | Values affected |
|---|---|---|---|---|---|
| 2026-10-26 | site | method_text | It said every read “never pretends to be another company’s crawler”. The census and scanner do send other crawlers’ user-agent strings, from CrawlCheck’s own addresses, to measure what those crawlers are served. | The page now says so, and how a firewall can tell those requests from the real crawler. Details | none |
| 2026-10-21 | site | disclosure | From 14 to 21 October, agents asking whether to pay crawlcheck.io were told “block” after an endpoint nobody had confirmed appeared on our own registry listing. | The change was ours and was confirmed; the block was the correct answer for an unconfirmed change. Written up in full. Details | none |
| 2026-10-14 | site | data_publication_error | Every standing page in the page sitemap carried the same last-modified date, 103 entries in all. | Each page now carries the date it last changed. Details | none |
| 2026-09-18 | vendor benchmark | measurement_error | Grades were published for sites CrawlCheck never reached - the homepage timed out or redirected in a loop on the apex and on www: fauna.com D/40, hippocratic.ai D/40, profound.dev D/40, robustintelligence.com D/40, milvus.io C/60 (plus blueheronrestaurant.com, registry only, since 2026-09-10). | An unreachable homepage is now recorded as no grade, with the reason (build 570). The six records were removed; the rows are re-measured by the directory job. Details | yes |
| 2026-09-16 | vendor benchmark | method_text | The measurement technique text said each site is fetched by "fifteen named crawler identities and one unnamed client". | CrawlCheck sends twelve named crawler identities plus an unnamed client and two mobile-browser controls; the text now says so in all three places. Details | none |
Findings disputed by site owners
1 disputes filed against a finding: 1 decided (1 finding stood, 0 changed), 0 open. Every decision is on the dispute ledger.
Report something wrong
Write to hello@crawlcheck.io with the page and what is wrong. A confirmed error is corrected where it appears and added to this log. Classes: measurement_error (CrawlCheck measured wrong), data_publication_error (the measurement was right, the published copy was not), method_text (a description of the method was inaccurate), disclosure (a decision that was correct but deserves an account).
As JSON: /corrections.json. Vendor benchmark corrections in detail: /directory/corrections. Changes that were not corrections: /changelog.