CoStar is the gold standard for commercial real estate data and listing intelligence. While it’s not a public-facing platform like Zillow or LoopNet, it powers many of them—including LoopNet itself—by supplying verified property data, analytics, and marketing tools to brokers, developers, institutional investors, and appraisers. If you're involved in commercial real estate, development land, or investment-grade properties, CoStar offers an unmatched depth of information.

With CoStar, users get access to nationwide property records, ownership history, zoning, leasing comps, demographic overlays, and real-time market analytics. It’s most commonly used by professionals for off-market research, asset evaluation, and strategic listing distribution. While individual landowners or single-property agents may find it overbuilt and expensive, brokerages and serious investors depend on it for market insights, pipeline generation, and valuation accuracy.