Buying a House - Maps and Data is an incredible website for anyone who is considering buying a house in the US, a renter who wants to understand the rental market, or just wants to know how much their house might be worth.

A realtor will have access to a database that includes more information (notably a more detailed history of the listings and sales for a property), but Zillow still has an amazing level of detail.

It lets you see houses that are for sale, those that have been sold, and provides a partial listing of available rentals (I don't think there is a centralized database for the rental market). It has a profile for 90% of the houses that features square footage, a listing/sales history, property taxes, date of construction, and possibly several photos.

One of the most important features in the Zillow Estimate (ZEstimate) of the value of each house. If you zoom in far enough on the map, you will see the estimated value of almost every house on a block. This gives you a good idea of the micro-market of each block. For instance, in my neighborhood the price of houses can differ by $50,000 for two adjacent blocks. Some of this can be explained by different house sizes and some of it is due to desirability (factors like: income, race, condition of houses on the block, and there is a school catchment zone in which houses cost $100,000 more). provides similar information but I found the website to be far less useful.