Who owns which domains

Why it exists

Concentration is invisible without it. Counted by hostname, Google looks like a dozen mid-sized third parties; rolled up, it reaches 79.8% of the entire web. Every ownership claim in the report runs through this file.

It is also a licensing decision. The well-known entity graph — DuckDuckGo's Tracker Radar — is published under CC BY-NC-SA 4.0: NonCommercial, and ShareAlike would force anything derived from it under the same terms. That makes it unusable for a site that carries sponsorship. So we curate our own from public corporate and ownership information, and publish it here.

How it's applied

• Deduplicated per page. An entity owning several domains is counted once per page in SQL, so a page loading four Google domains contributes 1 to Google's reach, not 4.
• Registrable domains only. Entries are eTLD+1, so every subdomain rolls up automatically.
• Ownership, not behavior. Being on this map says who operates a domain — not that the domain tracks you. Infrastructure and CDN entities are here for exactly the same reason, and the report marks them.
• Categories are the owner's primary business, not a per-domain judgment: Google is categorized as advertising even though gstatic.com serves static assets.
• Coverage is the head, not the tail. It maps the most-seen third parties, not every domain on the web. Unmapped domains still appear in the report — as themselves, in the domain-level table.

The map

Sorted by how many domains each entity owns. “Reach” is the share of pages in the 2026-06-01 crawl making at least one request to any of them, where we measured it.

Total mapped: 102 domains. Domains outside this map default to being treated as their own entity.