United States Real Estate Data
The US is the world’s largest online real estate market, led by Zillow, Realtor.com, Redfin, Trulia, Apartments.com, LoopNet, Homes.com and Crexi — and PropAPIS extracts all of them through one API. US residential portals alone draw ~500M+ visits per month combined, with Zillow’s database spanning ~160M+ US homes (Similarweb ).
Leading portals
The US market splits into a handful of dominant residential portals (Zillow, Realtor.com, Redfin, Trulia), a CoStar-owned rentals/commercial cluster (Apartments.com, LoopNet, Homes.com), and an independent CRE marketplace (Crexi). PropAPIS has a dedicated platform page for each:
The #1 US portal (~350M visits/mo) — listings, prices and Zestimate valuations.
Realtor.comThe #2 portal (~110M visits/mo) — authoritative MLS-fed listings and price history.
RedfinPortal/brokerage — strong sold data, price history and Redfin Estimate AVM.
TruliaZillow Group’s consumer portal — listings plus neighborhood data.
Apartments.comCoStar’s rentals leader — unit-level rents, floor plans, amenities and fees.
LoopNetCoStar’s commercial marketplace — cap rate, NOI, lease rate and building class.
Homes.comCoStar’s fast-growing resale portal — full MLS-fed residential fields.
CrexiIndependent CRE marketplace — ~$815B in active for-sale value and analytics.
Market overview
The US residential market is concentrated by traffic: Zillow (~352M visits/mo) leads, followed by Realtor.com (~110M), Homes.com (~55M), Apartments.com (~26-35M, rentals), then Redfin and Trulia (Similarweb — zillow.com ; realtor.com ). Zillow’s database spans ~160M+ US homes, while MLS feeds carry the bulk of the ~1M+ active US for-sale listings plus millions of rentals.
Ownership is heavily consolidated, which matters for data access. Zillow Group runs Zillow, Trulia and HotPads on a shared backend. CoStar Group is the largest single cluster — it owns Apartments.com (top rentals), LoopNet (top CRE marketplace) and Homes.com (a top-4 resale portal), plus the Homesnap and Land.com networks (CoStar press room ). Realtor.com is operated by Move Inc. under News Corp and is MLS-fed and authoritative.
Data richness varies by platform. Zillow is the richest single source — price history, the Zestimate AVM, rent Zestimate, tax history, photos, agent and days-on-market — but the hardest to parse. Realtor.com carries authoritative MLS fields; Redfin adds sold data, price history and the Redfin Estimate plus a public Data Center of free market datasets. For rentals, Apartments.com has the deepest fields (unit-level rent, floor plans, availability, amenities, fees, pet policy). For commercial, LoopNet and Crexi expose cap rate, NOI, price/sqft, lease rate, building class and zoning; Crexi additionally surfaces ~$815B in active for-sale value across 153M+ property records (PRNewswire ).