How this list is built

What gets listed

A site is listed if it aggregates supply across a whole US vertical and lets a visitor search or compare it. A single company selling only its own inventory is not a portal, with one deliberate exception: where a single-inventory brand has become the category’s primary search destination, it is listed and labelled as such.

Government systems are listed alongside commercial ones. In several verticals — moving, mortgage, behavioral health, broadband — the federal registry is the only source that is both complete and disinterested, and leaving it out would give a false picture of the market.

What is measured, and how

Each of the 61 industries carries a head keyword with its monthly US search volume, cost per click and advertiser competition index. These come from Google Ads keyword planner data via DataForSEO, location United States, language English, measured 2026-09-01 or later. They are not estimates and not scraped from third-party SEO tools.

The opening score combines those three numbers and nothing else. It is a filter for further work, not a verdict.

Link checking

All 149480 listed URLs are fetched before any registry change is merged. Roughly a third of US portals refuse scripted requests outright while working normally in a browser, so the check separates bot defence from a genuinely broken link: a 403 or a dropped connection on a host that still resolves is recorded and allowed, while a 404, a server error or a hostname that no longer resolves blocks the change.

Disclosure

US Portal Atlas is published by ROOT TEAM Inc., which operates portals of its own. Where one appears in this index it is marked Ours, listed under the same rule as everything else, and given no ranking advantage.