The TrafficWonk Web Index
TrafficWonk maintains a large corpus of known sites and domains, and independently observes a growing subset of them to establish current evidence of what is actually serving. Knowing that a site exists and having checked it are two different things, and TrafficWonk keeps them apart.
Current scale
Known sites, exactly: —
Known is not the same as observed
Every figure above means something specific, and the difference between them is the point of the architecture rather than a caveat hidden in a footnote.
Why the distinction matters
Large web datasets are not lists of working websites. A single corpus will happily contain domains that were merely linked to from somewhere, domains observed years ago and never since, sites that genuinely serve a business today, parked pages waiting to be sold, redirects to somewhere else entirely, and hosts that cannot be reached at all.
Collapsing all of those into one “websites” number produces a big figure and a misleading one. TrafficWonk deliberately does not do that. The Web Index records what is known; observation records what was actually found, when, and on what evidence.
How TrafficWonk learns about the web
Common Crawl is evidence that feeds the Web Index. It is not the source of TrafficWonk's observations: those are gathered independently by TrafficWonkBot, TrafficWonk's declared crawler, which respects robots.txt and publishes its behaviour.
Evidence, not guesswork
When TrafficWonk observes a site it does not immediately reduce the result to “alive” or “dead”. A domain can resolve but refuse connections. It can serve a page that is really a holding notice. It can be perfectly healthy and simply decline to talk to automated clients. Those are different facts and they are kept as different facts.
Each observation preserves dimensions such as:
Keeping the dimensions separate is what lets TrafficWonk say something precise later: that a site was reachable but restricted, or that it served a parked page, rather than flattening both into a single misleading verdict.
Related
TrafficWonkBot — crawler policy and allowlisting
The TrafficWonk Visibility Directory
Company information