HAR.com is the official search website for residential property in the Greater Houston Area.  This service is known as MLS, or Multiple Listing Service.

HAR, short for the Houston Association of Realtors, has an agreement to share their listing data with other home search websites, such as Zillow and Trulia, but just know HAR.com is the only website with the most accurate and timely data, as HAR is the source for MLS data.

So, if you are searching on any website other than HAR.com, then always check a property of interest on HAR to make sure the property is still available.  The Iillustration on this page shows the websites that have permission to publish HAR.com listing data.