Many homeowners go online to popular real estate websites such as Zillow or Trulia to search for homes for sale, or to find the sales price on the neighbor’s house down the street.

Real estate websites have transformed the whole consumer experience of home buying and selling as they make public the listing and sales data that for long was hard to get.

Several sites post nearby sales, with the promise that homeowners can input an address and find out what homes in the neighborhood have sold for lately. Zillow and Trulia take the leap from recent sales to placing an estimated value on your home.

Have fun browsing the neighborhood online, but be careful not to place too much stock on automated sales information. When it comes time to place dollar values on perhaps the biggest financial decisions of your life – buying and selling a home – check the computer but speak with a Realtor.

There’s value in details – big values. Acomputer can take the description of your home from public records and compare to homes nearby that have sold recently. But the computer won’t know or tell you why a house sold for what it did, or relate a property’s condition, or issues of motivation, nor correct for whether the house two blocks over was a fixer upper or highly upgraded showplace.

Zillow uses proprietary automated valuation models that apply advanced algorithms to analyze data within a specific geographic area. Home characteristics obtained from tax assessor’s data such as square footage, lot size, bedroom and bathroom counts are given different weight according to their influence on home sale prices over a specific period of time.

Using recent sales in the area, the algorithms apply a set of valuation rules to generate each home’s Zestimate. Sites try hard to check comparables and do the math, but they are at best, computer programs.

If you live in a housing tract or subdivision where several homes just like yours have sold recently, you’re likely to get a value estimate that is in the ballpark.

If you really want to know what your property is worth, no computer program is as accurate as a living breathing real estate professional who sees and sells all the different varieties of properties in the area, and knows first hand what ready, willing, and qualified buyers pay for them.

Adriana Donofrio • deasypennerpodley Glendora (626) 926-9700 • adonofrio@dppre.com