You can put your house on Zillow for free as in for sale by owner, however, the remaining information on the page is generated by Zillow and is usually quite inaccurate. I have no idea how an internet site can "zestimate" the value of your home (unless they are asking realtors). This can be pretty damning. The internet doesn't know when the house was reroofed, whether or not the neighborhood is safe, or when the furnace was replaced. I have consistently seen the square footage or property taxes NOT match the county assessor's website. I can only say that it's okay to look, but don't take their website information as truth. Buying a house is a big investment.