Not long ago, a homebuyer started a search with the Sunday newspaper.

Now it goes directly to Zillow or similar sites like Redfin or Realtor.com

A new buyer told Boston 25 News, “I use it all the time. We just bought our house a year and a half ago and I was obsessed with Zillow.”

Another woman told us, “I like Zillow. It’s very helpful and informative and just helps to narrow the search when doing it yourself on Google.”

These websites are a way to track properties that have grown faster than the price of a suburban single-family home.

“Zillow is the most visited real estate marketplace in the country, with nearly 200 million unique users per month,” said Amanda Pendleton, Zillow’s home trends expert.

But some backlash against these online platforms is now brewing, with some brokers saying they are actually doing buyers and sellers a disservice.

The core of Zillow’s appeal is the Zestimate.

“The Zestimate is Zillow’s best estimate of the value of your home,” Pendleton explained. “It’s an AI-powered computer algorithm that collects millions of data points, mostly public information about your home.”

“Unfortunately, an online algorithm is very inaccurate because every house has different variables and different characteristics,” countered Gene Hashkes, a real estate agent at William Raveis Real Estate in Newton.

Hashkes says that to really understand what a property is worth, someone has to see it in person. “The algorithm doesn’t take into account aspects like the condition of the house, whether a major issue like a roof or a heater has been replaced.”

Marie Presti from The Presti Group of Stoneham and Newton doesn’t trust the Zestimate either.

She says Zillow could look at two similar homes on the same street and rate them the same way, without considering that one sits on a nature reserve and the other atop a busy supermarket.

According to Presti, this can lead to a distorted picture of the overall market. “I’ve had sellers look at the Zestimate and feel like their house is worth $100,000 more and I have to say, but you have these adjustments and it’s difficult. . .but you also have to raise their expectations.”

“We like to say the Zestimate is an estimate with a Z in front of it,” Pendleton said.

She says the company believes Zestimate is a great starting point for both buyers and sellers. “It really is Zillow’s best estimate of what a home is really worth, and it doesn’t replace a great local agent.”

Home buyers and sellers we spoke to say these sites can be addictive. “It’s fun to look at, just see what’s out there and what the prices are like and what the market is like. I mean, I love Zillow.”

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