.co.us domains list

What is .co.us TLD

The .co.us TLD is best understood as a structured second‑level label within the United States country‑code space, .us. It is not a standalone top‑level extension; instead, .co.us domains sit beneath .us, historically reflecting locality-driven naming and U.S. presence requirements. In contemporary usage, .co.us websites appear in government, civic, and legacy organizational contexts, with policies following the wider .us eligibility (nexus) rules. From our global scans, we observe a compact footprint, stable naming lifecycles, and low churn relative to generic alternatives, which can benefit long-term citation and archival reliability. We map registrations, DNS, and hosting attributes to quantify reach and security posture across this namespace. Explore webatla’s .co.us domain datasets today.

History and key features of .co.us TLD

.co.us emerged within the early .us locality framework, where standardized labels (such as “co” for county) supported hierarchical addressing under state or municipal delegations. Over time, direct second‑level .us registrations grew, and many public entities consolidated onto .gov or state-run spaces, leaving .co.us domains concentrated in legacy deployments and specialized civic uses. Current .co.us websites inherit .us policy baselines: U.S. nexus requirements, RDAP-based registration data, and DNSSEC capability when operators enable it. We also note consistent naming conventions tied to geography and administrative units, which simplifies discovery and cross-referencing in our index. Our datasets quantify age, resolver diversity, TLS adoption, and availability trends across this slice of the .us namespace. Explore webatla’s historical .co.us domain datasets.

Why and who choose the .co.us domain

Organizations choose .co.us for clear U.S. signaling, geographic specificity, and alignment with county-level brands, particularly when continuity with established addresses matters. We see .co.us domains used by county governments, archives, records systems, and vendors supporting public-sector portals; some .co.us websites persist as redirects or stable endpoints for legacy applications. Advantages include predictable naming, lower namespace contention, and strong association with public administration; considerations include user recognition and potential confusion with Colombia’s .co or company-style “co” branding. Our analytics reveal long-lived registrations, modest traffic spikes tied to civic events, and variable security hardening across operators. For risk, branding, or research decisions, empirical evidence outperforms assumptions. Explore webatla’s curated .co.us domain datasets.