15.9 million domains the census could not pin down

A domain is supposed to be up or down. The September 2026 census found 15,865,500 that were neither: 4.56% of the delegated inventory answered enough to prove they exist and not cleanly enough to be graded. They are the indeterminate middle, larger than the strictly dead population by more than ten to one.

Between alive and dead

The census sorts every delegated name into alive, dead, or indeterminate. Dead is small and definite: 1,389,076 names that no longer resolve at all. Indeterminate is more than ten times that, 15,865,500 names that returned something, then contradicted it, timed out on a step that had worked, or resolved through a delegation that answered for some queries and not others. The scanner could not turn that into a grade, so these domains fall out of the graded 316.6 million and into the dark matter alongside the strictly unreachable.

Be precise about what this figure is. It is the count of domains that could not be pinned down on the pass that ran. It is not a measurement of uptime or of how often a domain answers, because the census does not probe a name repeatedly to clock its flakiness. The honest word is indeterminate, and the honest reading is that a domain in this bucket has something unstable in its resolution path, most often a nameserver or a delegation that half-works.

Why a reader should care

The indeterminate 15.9 million is the reason a careful census reports its denominator every time. A grade share stated against everything delegated silently includes these names; stated against the graded set, it does not. The gap between the two denominators is exactly the population on this page plus the unreachable, and it is why the counting page exists and why edition-to-edition percentages are not a clean trend.

See your own

If your own domain lands here, it resolves sometimes and not others, which visitors and mail receivers experience as random failures. The free scan will show the step that breaks, which is where to point your DNS provider.

Figures as of 5 September 2026, from the September 2026 edition of the defaults.exposed census. Census numbers move every month; the current values are on the data page.