It’s so easy to go to a popular real estate website, enter your home address, click on a button and then bam! In an instant, a webpage appears with your “home value”. Today, there’s a plethora of online home valuations. It almost feels like an ice cream store, because they come in so many different flavors.

But do these online home valuations really work? Short answer: no. They are never as accurate as an estimate from a real estate professional who knows your local market and your home. Studies have show even the best ones can be off by 30% or more.

Just ask Zillow’s CEO. He sold his home in Seattle for $1.05 million. The Zestimate on his home: $1.75 million.