Your home is usually your largest investment. There are few other things in life you will ever invest money into that offers the same positive ROI as your residence. Knowing what the current market value is on your property is crucial in property tax assessment contesting, refinancing and selling.
Working in real estate, I came across a smattering of sellers convinced that their true home value could be gleaned completely from the internet. While not all of the websites are inimical, there is certainly no accurate way to determine your home value to the nearest dollar without a real estate agent. However, since the internet is part of all of our lives, I can give you some tools to watch out for and ratings of websites out there from a seasoned pro's perspective; using a rating system of one to five stars.
Epraisal - Five Stars
Truly this is one of the best websites for gleaning the value of your home, as the data is derived from the sales statistics in regional areas directly from the MLS (Multiple Listing Service). What it doesn't do, however, is mention seller concessions in the total price, but, for an overall idea of what your home is worth, this is superb jumping off point.
Realtor.com - Five Stars
Similar to the data collection function on Epraisal, I give Realtor.com a whopping thumbs up in a variety of areas. It's a one stop shop for sellers, pulling data directly from the MLS for current listings and recently sold properties. They are also the brainchildren behind Top Producer's Market Snapshot; a service provided by real estate agents for which a seller can receive regular email updates on his home value at any time.
Homegain - Four Stars
Homegain is a connection portal designed to bring real estate agents together with buyers and sellers. When I worked in real estate, I picked up some terrific clients from this website, and enthusiastically endorsed it
to my fellow agents. The Homegain seller gateway allows sellers to sign up and receive email information and home values on a monthly basis. The user friendliness of the website is the only thing decidedly lacking here, which is why I consider it four stars.
Trulia - Three Stars
Truila gets three stars because it is a hit and miss website when it comes to values, currently listed property and recently sold properties. Most of the home value data displayed on Truila comes from the local county tax assessors office, but the information not always up to date or on par with current market snapshots.
Zillow - Two Stars
Zillow is not my favorite. Not my favorite by far, especially with the release of the Z-estimate. Since many of Zillow's listings and information services rely heavily on updates from real estate agents, (which doesn't always happen) the validity of the data is somewhat uncertain at times.
The best way to find out your home's value is from a local real estate agent, bar none. Seasoned professionals often offer market analysis for a variety of reasons at low or no cost to the seller. For real estate agents, I add another star. When you get a report from a Realtor, you get a six star rated home value report.