Recently my research team completed an analysis of ~4.3 million domains spanning 2025-12-01 to 2026-03-31, identifying approximately 1.25 million potential clusters (i.e. associated domain groups).

Here's our cluster breakdown by detection strategy:

• Prefix + TLD clustering (Strategy A): ~469K clusters — domains sharing a fixed alphanumeric prefix with variant suffixes under the same TLD. (example below)

• Exact apex clustering (Strategy B): ~726K clusters — identical second-level domain registered across multiple TLDs.

• N-gram fuzzy clustering (Strategy C): ~50K clusters — near-duplicate apex names detected via trigram locality-sensitive hashing.