A searchable record of which advertising networks monetise which websites — built from the files the networks and the sites publish themselves, and shown with the evidence attached.
Every serious ad network publishes a sellers.json file: its own list of the publishers it is authorised to sell for. Every serious website publishes an ads.txt file: its own list of who is allowed to sell its inventory. Each file is one side of a business relationship, stated in public, in a machine-readable format the industry agreed on. WhichAdNetwork reads both sides nightly, cross-checks them, and turns the result into pages you can browse: every network, every site, every niche.
The point of the cross-check is trust. A network saying it works with a site is a claim; the site's own file naming that network's seller account back is a confirmation. Rows on this site are labelled accordingly, and the method page explains exactly what each label requires.
Only from public, attributable records: the seller files networks publish at their own domains, the ads.txt files sites serve at theirs, and — where a site publishes no ads.txt — the ad scripts visibly present on its homepage. Nothing is inferred from private data, paid panels or browser tracking, and every page shows the verbatim evidence lines it was built from, so you can check any claim against the source yourself.
WhichAdNetwork is a small independent project, not affiliated with any advertising network listed on it. Questions, corrections and takedown requests all reach a person at [email protected]. If something on the site about your network or your website is wrong, the report page explains how to get it fixed — and because every row is rebuilt from the public record, a correction at the source corrects it here too.