Local Knowledge. Shore Results.
Zillow, Redfin and Realtor.com each calculate home values differently. For homes that aren't for sale, Zillow and Redfin both report that half their estimates miss the eventual sale price by more than about 7%, which on a $500,000 house is more than $36,000.
Type your address into Zillow. Then Redfin. Then Realtor.com. You'll get at least three different numbers, and if you log in to Realtor.com, that site alone will show you three more.
If you're thinking about selling, you've probably done this already. It's natural to hold onto the number you like best. Buyers and their agents are looking at the same sites, so it helps to understand where each number comes from.
Here's how each site builds its estimate, how accurate the companies say they are, and how to use these numbers when you're getting ready to sell.
How Zillow Comes Up With the Zestimate
Zillow runs its own model, a neural network that pulls from county and tax assessor records, direct MLS feeds, home details owners enter themselves, and market trends like seasonal changes in demand.
Zillow's FAQ is upfront about two things. Additions, updates and remodels that were never reported to the tax assessor aren't reflected in the Zestimate. The model can also use data from an area as large as a county. In Ocean County, that means a lagoon house in Forked River and a ranch on a dry street in Toms River can end up in the same pool of data.
Even the work that does get reported takes a while to show up. From my years working for Manchester Township, I can tell you Ocean County records typically run at least three months behind. Finish an addition in March, and the county may not show it until June or July. Until the records catch up, any estimate built on those records is still valuing the house you used to have.
Sales have the same lag. When a house closes, the closing attorney reports the sale, and it takes the same slow trip through the county before it shows up in public records. Zillow and Redfin both pull sold data straight from the MLS, which helps when a house was listed with an agent. A sale that never hit the MLS, like a private sale or a for-sale-by-owner, only shows up once the county records catch up.
How the Redfin Estimate Works
Redfin is a brokerage, so it has direct access to the MLS. Redfin says its model weighs more than 500 data points, including details like a water view or a busy street, and picks comparable sales from nearby homes that sold recently with similar features. Estimates update daily for homes on the market and weekly for everything else.
No online model can walk out back and see the condition of the bulkhead. That takes someone standing in the yard.
Realtor.com Shows You Three Numbers
Realtor.com licenses its estimates from three data companies: Cotality (formerly CoreLogic), Collateral Analytics and Quantarium. These are the same kind of valuation firms lenders and insurance companies use. If you're not logged in, you'll see one headline number. Log in and you can see all three side by side.
Realtor.com doesn't publish an error rate for these estimates, so the most useful way to read them is as a range. If the three numbers are close, that's a good sign. If they're far apart, it usually means your house has features the data has a hard time measuring.
Until the records catch up, any estimate built on those records is still valuing the house you used to have.
How Accurate Are They?
Zillow and Redfin both publish their accuracy numbers. As of November 2026:
- Zillow: 1.80% median error for homes on the market, 7.21% for homes that aren't
- Redfin: 1.93% median error for homes on the market, 7.59% for homes that aren't
A median means half the estimates come in closer than that, and half miss by more. Redfin's own numbers show that nationwide, about 6 in 10 off-market estimates land within 10% of the eventual sale price.
On a $500,000 house, a 7.21% miss is $36,050. Some estimates land much closer than that, and some land further off.
The 1.8% Only Applies After the House Is Priced
The 1.8% figure gets quoted a lot. It only applies to homes already for sale. Once a house is listed, Zillow says the Zestimate starts using the listing information, including the list price. The most accurate version of the estimate shows up after someone has already priced the house.
If you're still deciding whether to sell, your house is off-market, and the 7% numbers are the ones that apply to you.
How to Use These Numbers When You're Selling
Pricing off the highest estimate is a common mistake. Buyers compare your house to the ones that actually sold, and when a price is out of line, they keep scrolling. The longer a house sits, the more buyers wonder why. Zillow also notes that a home listed longer than is typical for its market can switch back to an off-market estimate, which can widen the gap between your price and the number buyers see.
It works the other way too. If you put on a new roof, redid the kitchen or raised the house and the county records haven't caught up, the estimate can come in low. Pricing off that number can leave money on the table.
One thing that helps: claim your home on Zillow and update the facts. If the data is wrong or missing, correcting it can change the Zestimate. Zillow and Redfin both say the same thing about their own estimates: use them as a starting point, then get a price based on your actual house.
What Actually Sets Your Price
Recent sales close to your house, adjusted for what's inside it. The condition buyers see when they walk through the door. What else is for sale right now in your price range, and what those buyers are choosing. That's what a comparative market analysis is built on, and it's what both companies recommend pairing with their estimates.
Curious how the websites compare to what's actually selling near you? Reach out directly or call (609) 709-2742 and I'll pull the recent sales near your house so you can see them side by side.
Matt Quinn
United Real Estate Associates
(609) 709-2742
matt@mattquinnsellshomes.com