CoStar Group is the largest provider of commercial real estate data and analytics. It collects data on over 4 million properties totaling over 81 billion square feet across various sectors like office, industrial, retail, and apartment. CoStar provides comprehensive third-party data, reports, and tools to help users identify available properties, research markets, compare sales, evaluate leasing opportunities, and gain insights. Its suite of online products and mobile app CoStarGo deliver property listings, leasing and sales comps, tenant information, and analytics to help users close more deals.