A Real Estate Discussion Blog


How Accurate Are Zillow's Zestimates?

I recently attended a trade show where the two most popular questions at the Zillow booth were 1) Where do you get your data and 2) How accurate are your Zestimates?

DataWe get data from a number of sources, but the most popular place is from county records.  In some counties this is great, in others (especially in non-disclosure states)  the data is very weak and we have to turn elsewhere.  Of particular note to Agents- we also get data from listing feeds.  Say the county said a home had 3  bedrooms, but when you post the listing on Zillow you say it has 4.  We will override he county data with your information, as we figure you are the more reliable source, and the Zestimate could change based on this.  If you want to read more about the Zestimate, please visit What's A Zestimate Value.

Accuracy  -  We constantly monitor how accurate the Zestimates are by comparing them to closed transaction data on the day the property sells.  By looking at the deltas that exist between the Zestimates and the sold prices, we can conclude our median err (or accuracy) rate.  We then publish these figures across all counties.  We are the only AVM (automated valuation model) to be publically transparent about our accuracy rates.  On this chart you'll also see the percent of times that the Zestimate was with 5, 10 or 20% of the sales price. 

This Accuracy Chart can be found at the bottom of all Zillow pages as a light gray link called Zestimate Values & Accuracy. Click on the link, then click on States/Counties and scroll to your area.  So when we were asked this question, we simply went to the Accuracy Chart, looked up the accuracy rate, and gave a straight answer. 

This accuracy rate can also effort the Value Range we have on many of the 80 million homes found on Zillow.  If the accuracy is low, the value range spread may be much wider than if the accuracy were high.  Having the value range on properties at all is a good indication to folks that the Zestimate isn't an appraisal, but rather a starting point and thus the need for a range. 

Many Agents said this chart was very helpful because they work with clients who will say "but Zillow said..." about a home's particular price.  Now they can come back and say "but Zillow also said that they have an err rate of XX% in our county" and have the numbers to prove this. 




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Comment balloon 92 commentsSara Bonert • December 23 2008 09:33PM


Since Texas is a non-disclosure state, all Zestimates for Texas should be suspect.

Posted by Lorrie Semler, REALTOR® in the Dallas area. Call/text 972-416-3417, Real Service. Real Results. Real Estate (United Real Estate) about 11 years ago

Yeah, TX is tough.  As a state, we have a median err rate of 12.9%.  But we do get a lot of data from other sources, in an effort to compensate for not getting public record data. 

Posted by Sara Bonert, Real Estate Internet Marketing (Zillow) about 11 years ago

I always thought that stuff at the bottom was the disclaimer "fine print" and never looked at it.  Actually, their accuracy data is very important to have, especially for my area which only gets 2 stars for accuracy.  Thanks.

Posted by Richard T. Dolbeare, R(B), R(B), ABR, CRS...Hawaii Multi-Island Specialist (eXp Realty) about 11 years ago

I have found the Zillow to be fairly accurate.  Of course there are...and probably alway will be...some estimates are not even close to reality.

Posted by Chuck Capan, REALTOR Licensed In IL. - Moline Homes Quad Citie (REMAX River Cities) about 11 years ago


I never noticed the accuracy table before - thanks for pointing it out.  I too have had clients that have stated "but zillow said the house is worth xxx."   Enjoy the holidays.


Posted by Judy Jennings, Broker - The Lanterns at Warren Woods - Ashland MA (The Green Company) about 11 years ago

I dont think that zillow is very accurate as it doesnt really gague the market accurately!

Posted by Team Honeycutt (Allen Tate) about 11 years ago

Thanks for the info, I didn't know about the accuracy table.  I have had a few people ask me about the accuracy of zestimates lately.

Posted by Patricia Beck, Colorado Springs Realty (RE/MAX Properties, Inc., GRI, CDPE) about 11 years ago

Sara, Thanks for doing the research on this. It is very helpful.

Posted by Barb Szabo, CRS, E-pro Realtor, Cleveland Ohio Homes (RE/MAX Trinity Brecksville Ohio) about 11 years ago

I will just can in the big boys for estimates. This is really good info. If I know anyone who want to market in Chicago I will give them your name and number...


Marshal Dane Bethea

Posted by Marshal Bethea (Exit Extreme Realty ) about 11 years ago

Thanks for pointing this out to me.  Have a Merry Christmas

Posted by Russ Ravary ~ Metro Detroit Realtor call (248) 310-6239, Michigan homes for sale ~ yesmyrealtor@gmail.com (Real Estate One) about 11 years ago

Hi Sara:

Nice job pointing out the accuracy for your data; kudos for being upfront with how you derived your numbers. Agents could learn a lesson from your example.... but in reality, you don't really have to sweat it.

Just look at most of the actual pricing of listed homes around the country and you will conclude, I'm sure, that accuracy isn't a common concern for agents anyway.

Tongue firmly planted in cheek...

:> Happy Holiday

- Matthew

Posted by Matthew Ferrara, Matthew Ferrara & Company ( -- www.matthewferrara.com) about 11 years ago

THat's interesting that they're giving the Dallas market 4 stars when we're a non-disclosure state, and they aren't privied to closed sale prices.  They're wrong way more than what they're saying.

Posted by Donna Harris, Realtor,Mediator,Ombudsman,Property Tax Arbitrator (Donna Homes, powered by JPAR - TexasRealEstateMediationServices.com) about 11 years ago

I received an automated alert on my own residence noting that the property value had changed by $1500.  Wow.  You guys are good.

Posted by Paul Slaybaugh, Scottsdale, AZ Real Estate (Realty Executives) about 11 years ago


I have always considered Zillow to be suspect in their information.

Posted by John Douglas (Berkshire Hathaway HomServices Partners Realty) about 11 years ago

Zestimates are a great indicator on house values but I've never had a Zestimate match an appraisal.  Most of the time I find the Zestimate to be much higher.  However that could just be due to my area.  It may not be like this everywhere.

Posted by Justin Ukaoma, Kansas City Real Estate Investments (Vizion KC) about 11 years ago

Hello Sara,

Being from Texas I also was suspiciopus of Zillow info but I do think it provides a starting point for the seller.  Thanks for the info and Merry Christmas-Happy Holidays.

Posted by Charles Gardner-Realtor/Investor (ZIP Realty, Inc-Houston District) about 11 years ago

I have not found Zillow to be accurate here in the Bay Area.

Posted by Terry Osburn, Broker Associate (BHHS|Drysdale Properties) about 11 years ago

It is commendable that Zillow compiles and publishes accuracy data. With so many clients getting their real estate information online, this is a great tool for agents to use when discussing pricing, value and integrity of online info.

Posted by John Novak, Henderson, Las Vegas and Summerlin Real Estate (Keller Williams Realty The Marketplace) about 11 years ago

Hi Sara - a timely Blog.

My 2 cents are that Zillow is yet another "tool" but far down the line of sources deemed reliable.  I prefer to go straight to the source - County Data versus trying to use sites that massage data, etc.  Perhaps one day they will become more of a standard but for now.................


Have a peaceful and happy holiday season!

Fred T

Posted by Omega Omega (Omega) about 11 years ago

Sara -

Thanks for the update - good to see a fellow Chicagoan featured once again.

On a home we sold in the Portage Park Neighborhood, on the Northwest Side of Chicago, our client pulled a "Zestimated Value" of $250,000 a couple of days before we closed - for $187,000!  She was hot!

Indeed, the same house might have sold a year or so ago for the higher Zillow number, but, unfortunately, not today.

Often times, Zillow numbers provide a good general price guideline.  Other times, however, they are off - sometimes, substantially!

Happy Holidays, and Call or Stop By, the next time you're in Lincoln Square!


Posted by Dean Moss, Dean's Team Chicago IL Real Estate Team (Dean's Team - Keller Williams Realty Partners Chicago IL) about 11 years ago

Sarah: Great information. I have wondered this same thing as I have seen a differnce in Zillow and an actual CMA.

Posted by Roland Woodworth, Q Realty - Power In Real Estate (Q Realty) about 11 years ago

Zillow estimates are a fun tool to look at, but I rarely see the value being that accurate. 

Posted by Morgan Evans, LICENSED REAL ESTATE SALESPERSON (Douglas Elliman Real Estate) about 11 years ago

Hi Sara,

I recently had a very good appraiser say that Zillow's estimates are getting more accurate.  He said that it was his experience that they were running about at a 96% accuracy.  Amazing! 

Thanks for the post.

Posted by Jodi Bakst, Team Jodi - Chapel Hill Real Estate, Durham Real E (Team Jodi Realty) about 11 years ago

The problem in our area is that you pick up a house across the street from each other when one might be waterfront and the other might not even have a view.

Posted by Jean Groesbeck, Broker, CRS, e-PRO, ABR, ASP, CNE, IMS (Compass) about 11 years ago

I have seen off as much by 50% especially in declining markets and high end markets.

Posted by Kuldip Malhotra about 11 years ago

Wow! Great info about Zillow and how to address consumers when they rely too heavily on it. Thanks for passing on such great, usable, applicable info! Great use of graphics in your blog post too! --James Wirth

Posted by James Wirth about 11 years ago


I was logging on to ask for help in determining a price for a beautiful home on 3 acres that has zero comps for the oast year. Thak you for your comments. I'll check the zestimate anf if anyone out there has a better suggestion, I'm open


Posted by Kieran and Cecelia Loughman (Exit Creative Reaty) about 11 years ago

I am really glad to know about the accuracy rating, that will really help when I have sellers talk to me about Zillow.

Posted by Caren Wallace, Portland Caren Real Estate (Premier Property Group LLC) about 11 years ago

Thanks for the post...Zillow is fun, kinda like listening to your liberal friends...you know they are not correct or accurate, but they are still fun to hang out with.

Posted by Rob Kelly, Louisville Colorado Realtor (RE/MAX Alliance) about 11 years ago

When Zillow first came out the were 1.5 to 2 times too high.  Now they are much closer and is a better tool.  It doesn't provide the up to date information needed to understand current market conditions.

Posted by Mark Watterson, Utah Real Estate about 11 years ago

I don't see very much accuracy in our area.  With extremely diverse housing stock and tremendous waterfront/waterview areas, simple math from a remote location simply does not work.  Also, strength/weakness in employment is not accounted for as well.

Like politics, all real estate is local.

Posted by Arthur Chapman (William Raveis) about 11 years ago

If you are looking in a neighborhood with LOTS of recent comparable properties that have sold, zillow isn't bad.  But if the comps aren't really there and it is a more tricky kind of a listing, then zillow's estimates are not that correct most of the time...

Posted by Mike Klijanowicz, Associate Broker @ Cummings & Co. Realtors (Cummings & Co. Realtors) about 11 years ago

I met an appraiser last week (at the house about 20 minutes :-) at a 6 year old home that has sold twice and his estimate was within 3K of the Zestimate I looked up when I got home. His was lower by 3 thousound, by the way! (home sold for around 199,000.)

Posted by Michael Gault (A to Z Home Inspections) about 11 years ago

I agree with Michael's comment above.  It is pretty easy when there are a lot of comps and all the blocks are the same for the most part.  But in some areas block to block makes all the difference in the world and the Zillow estimate will not account for that or will not account when there are only a few sales.  Like anything else, it is a resource and as agents, it is good to know about it.  Great post !

Posted by The Somers Team, Delivering Real Estate Happiness (The Somers Team at KW Philadelphia) about 11 years ago

It is Christmas eve... and I am blogging????

Merry Christmas Sara!

Posted by Robert Rauf (HomeBridge Financial Services (NJ)) about 11 years ago

Sara - Great post with great information.  I also noted that when you're looking at the accuracy charts, you can download the information in Excel format.  Might be a good idea to have one of these printed out on a listing presentation to handle the "But Zillow said..." statements.  I like Zillow for the idea of it, but would never rely on its data as a consumer or an agent.  It gives you a basis for some thoughts on pricing, but definitely wasn't designed to be a internet-based CMA (and I don't think that was Zillow's intention, but some consumers use it as such).  Living in TX I often scope through Zillow to see what they have to say, but as we are a non-disclosure state, I often start my conversation with clients with that simple fact.  Although I know Zillow makes a good effort to pull info from other sources, the fact of being in a non-disclosure state makes it much harder for them to nail down numbers as easy.

Posted by Matt Stigliano (Kimberly Howell Properties (210) 646-HOME) about 11 years ago

Too many people believe what they see and hear on the 'net. I've had sellers think their home was worth way more because of Zillow. I've also had sellers believe their homes have appreciated 6% per year and have doubled in value in the past six years because NAR said so. Since neither have been accurate for our area, it is very difficult to get sellers to believe otherwise with local statistics.

Posted by Jim Dvorovy, REALTOR - Canton Ohio Real Estate (Cutler Real Estate) about 11 years ago

Sara - thanks for the explanation. Things seem to have gotten better,but a margin of error of 10% and more seems pretty substantial.

Now if they could just stop reposting listings that have been sold, or having 3 or 4 of the same listing posted. How confusing is that?


Posted by Jeff Dowler, CRS, The Southern California Relocation Dude (eXp Realty of California) about 11 years ago

in greater phoenix, the estimates are too varied. a mile radius changes comps dramatically and zillow doest not necessarily recognize that well enough (just my opinon)

Posted by James Wexler (wexzilla.com) about 11 years ago

I always wondered. I used several times first before contacting a listing realtor and found it to be a good tool.

Posted by SacramentoCommercialLoans Bank Turn downs welcomed, Quick closings 916-847-7212 (Sacramento commercial loans) about 11 years ago

In SouthEast Florida I have seen very inaccurate data from Zillow, to a point where I consider the information to be dangerous and misleading. I met an agent who informed me that he uses Zillow as a tool to show to his potential buyers that the price they are getting is actually a bargain, WHICH IS NOT TRUE! Careful with Zillow, make sure you have the most recent info in your area.

Posted by Peter Balogh, Reis Realty (Reis Realty Inc) about 11 years ago

Zillow estimates are only based on the sale price from the last time a sale was completed on the property.  It does not take into account: interior updates, renovations and complete overhauls of the property. It does not take into account the existing condition of the property when sold last either....worthless site IMHO.  Unreliable at best. INACCURATE estimates and unusable!  Anyone who considers pricing their listings off that site would be doing their clients a disservice.  (Appraisers using this site for numbers are unethical and unprofessional as well).

Posted by Kathleen Garvey, Denver's Neighborhood Expert - Listings & Sales (HomeSmart Cherry Creek - Denver) about 11 years ago

Um.....what PLANET is everyone on??? What are you guys smoking and can I have some?  These are at best GUESSTIMATES.  In my area Zillow is a mess that just sucks away business and makes the business I get 50 times harder bcause their GUESSES are generally so off the mark.  I wish that "pseudo-agent interlopers" like zillow could be slapped with  liability suits for the problems they cause.  Homes actually go unsold because of you guys.  I think the sellers should be able to slap you with a nice big suit when deals fall through because a zillow zestimate is off. The whole thing is ridiculous.   That certainly would shut them down and good riddence.  Recently, I saw a home with a GUESSTIMATE of $835,000. It sold for $1,150,000...that's over 25%!  That's not a zestimate that's a guess...a bad one at that.   We have comps in our area that aren't even in the same town of the subject property.  Comps from totally unrelated neighborhoods are common.

10% of $500,000 (a low end house or mid-range condo for my area) is $50,000!  5% is 25,000.  HELLLLOOOO...there are some real life consequences to all of this and it isn't pretty.

Posted by Ruthmarie Hicks (Keller Williams NY Realty - 120 Bloomingdale Road #101, White Plains NY 10605) about 11 years ago

I really like the Zillow estimates.  However, we advise home owners not to rely on the data for pricing their properties for sale. We want to verify the figures with current comps.

Posted by Roy Kelley (Realty Group Referrals) about 11 years ago

I think that the Zillow error data needs to be connected directly to the Zestimate.  In looking at the Atlanta area, the estimate is within 20% only 2 of three times... 20%...  That means for a house with a $300,000 value, Zillow's range of $240,000 to $360,000 is wrong for 1 of three homes... but the range given is tighter than that and according to Zillows numbers has a higher likelihood of being wrong than right...

Posted by Lane Bailey, Realtor & Car Guy (Century 21 Results Realty) about 11 years ago

Thanks for the post,, and I found all the comments helpful.

Posted by Rebecca Gaujot, Realtor®, Lewisburg WV, the go to agent for all real estate (Vision Quest Realty) about 11 years ago

Zillow is just another tool.....bottom line is they do not have all the information needed to get the real numbers.... many clients are starting to understand its just there insight on value. Never rely on that site to get the information that you need.

Posted by Nancy Birge, Waterfront Specialist (Coldwell Banker) about 11 years ago

Sara, good article that home sellers should read along with home buyers who fail to examine the error rate and the value percentage.

Posted by Gena Riede, Real Estate Broker - Sacramento CA Real Estate (916) 417-2699 (Riede Real Estate, Lic. 01310792) about 11 years ago

My verdict is still out on Zillow. Seems like the best source of information for a local market is a local agent, and the local MLS.

Posted by Keith Strawn, www.ExploreBeaufortRealEstate.com (www.ExploreBeaufortRealEstate.com (Ballenger Realty)) about 11 years ago

Thanks for sharing! I haven't found Zillow to be very accurate in my area, but I never knew I could check their accuracy score. I'm off to do that right now! Thanks again, and Happy Holidays!

Posted by Kristen Wahl, CBR (Re/Max Plus) about 11 years ago

My verdict is not out on Zillow I have ruled on this -- I wish I could buy the home in my market neighborhood for the price they have estimated -- 30% on average I would say they are off -- Thanks for the info --

Posted by Jason Ellis (Coastal REO Solutions - Myrtle Beach Short Sales & REO's) about 11 years ago

it is a very dangerous idea to use a zestimate to price your home for sale. There are way too many variables in pricing a home to let a computer program price your home.

Posted by Mike Russell, Overland Park Kansas Real Estate (Mike Russell & Associates) about 11 years ago

Helpful to know there is an accuracy chart. The public needs to know that zillow is there more for fun, not a tool to use when setting the price of their house for sale. Of course, it doesn't help that the media uses statistics from their site. Makes it look like they're a reliable source of information for every part of the nation.

Posted by Stephanie Davis, Broker Associate and REALTOR® (The Boulevard Company) about 11 years ago

Thank you for pointing out the error percentages. That is good information.

It also goes along with our studies that show about + or - 25% on valuations in Ann Arbor.

I do really feel sorry for people who actually think it is accurate. I had a couple interested in home buying who thought they had "found the answer" with Zillow.

Kind of like getting medical advice from a phone operator in another country.

Posted by Jon Boyd, Ann Arbor Real Estate Buyers Agent (Home Buyer's Agent of Ann Arbor) about 11 years ago

As any home can vary 15% based on its condition, it is absolutely rediculous for anyone to consider a computer computation rather than an individual.  Saw a for sale by owner that sold his home at 100% of value in 2 weeks on Craig's List.  I did not have the heart to tell him that he priced it 20% below market ($150k below).  Well, he's happy and I guess that's all that matters for him.

Posted by TIM MONCRIEF, Over 2,000 homes sold….. (Tim Monciref) about 11 years ago

Sara - Based on the chart that you provided in your post, it would seem that the answer to the question posed in your title is, "Not very accurate."  We've all sort of known that for awhile.  Sadly, many consumers don't understand this, so they assume some measure of accuracy.  It looks like you have to get to the "within 20%" category in order to have a majority of homes covered.  20% is HUGE.

I appreciate the effort to be more transparent with your data, but it seems so far out of whack that it's simply irresponsible to publish Zestimates in the first place.  You said in your post that the accuracy chart could be found "at the bottom of the page as a light gray link".  Sounds like most people would never think to look there, which might have been the intent. 

Perhaps Zillow could regain more respect from agents by removing the Zestimates altogether and sticking with the "value range" concept.  At this point, the Zestimates seem to provide nothing but headaches for those of us actually selling homes. 

Posted by Jason Crouch, Broker - Austin Texas Real Estate (512-796-7653) (Austin Texas Homes, LLC) about 11 years ago

Hi Jodi, the only thing I can say about an appraiser that says zillow is 96% accurate , "I hope he doesn't move to Florida." Do they adjust for the conditions of the sale, ie: seller contribution, type of financing, actual condition of the home, was there a death/divorce? We as agents have to know the things, even on a  ERC or BPO they want to know the Conditions of the sales. I have not found them to be that helpful. I think appraisels are to complicated and have to many veriables to be done from just whats in public records. 

Posted by Ann Hayman, GRI,CDPE,IRES, Jacksonville, FL. Gated Communities , Real Estate (Norville Realty) about 11 years ago

Texas is a non-disclosure state and nobody ever quotes Zillow down here.  I feel sorry for you guys up there.  I would just tell them that nothing replaces the realtor's knowledge and expertise.  You have all the experience and the access to mls, and you've seen a lot of the houses. Those stupid sights are just a guess.  Ya, I guess I could self diagnose my medical conditions off the internet as well without seeing someone with an M.D. behind their name!

Posted by Jeff and Lisa Sellers (The Sellers Realty Lubbock,TX) about 11 years ago

Everyone- Thanks for the comments.  Sorry I haven't chimed in more, but it is almost Christmas Eve and the celebrations are beginning to start with my family!  If anyone has anything they directly want an answer to, please feel free to email me and I'll be sure to respond. 

The general feeling of the comments here is that the numbers are just a starting point and not to be used at all in an official capacity- which is exactly correct in what the Zestimate is supposed to represent. 

To those in TX- We have contracted with MLS's in some areas of Texas to use sales data for computation. We also use public record data on loan amounts to impute loan to value ratios. Finally, as I mentioned in my post, we also use some data that we receive in the actual listing feeds.  So there are other sources for us to pull from, outside of public records. 

For those that are really into data and methodology, you may enjoy this blog post our VP of Analytics did which compares Zillow's methodology in determining trends (national and local) verses that of OFHEO and Case-Shiller.  May explain why the media likes to use our data.

I also want to point out, that not only can this chart be found in the footer of each page, there is also a link to it next to every Zestimate on the site.  Whenever we publish a Zestimate, you'll notice a little "?" next to the number.  When you click on this, it pops up a box with links that explains what the Zestimate represents and also give a link to the accuracy chart mentioned.  It looks like this:

 Happy Holidays to all!

Posted by Sara Bonert, Real Estate Internet Marketing (Zillow) about 11 years ago

I like how everyone is upset that Zillow makes "guesses" at price but the vast amount of overpriced inventory sitting for MONTHS on the market are somehow "priced right" because they were priced by REALTORS in their super-accurate MLS???

Here's something nobody seems to be noticing: CONSUMERS BELIEVE ZILLLOW. For better or worse. On the Trust-o-meter, consumers are more likely to believe the Zillow/computer than they are to believe an agent report.

If you don't believe it, then ask yourself how many "Oh, exactly what we were thinking!" listing appointments you had last year....


- Matthew

Posted by Matthew Ferrara, Matthew Ferrara & Company ( -- www.matthewferrara.com) about 11 years ago

I have had many clients look at Zillow for values but was not aware of the posted err rate for different areas.

Posted by Christine Donovan, Broker/Attorney 714-319-9751 DRE01267479 - Costa M (Donovan Blatt Realty) about 11 years ago

I have found Zillow values all across the board. Some very high, some very low, some right on. The question becomes, is the value Zillow applies to MY home in the "right on" category? I would say you have a 1 in 3 chance.

Posted by Scott Baker, Realtor Homes for Sale in Cincinnati, West Chester, Mason, OH Area (www.eHomeReports.com Coldwell Banker West Shell) about 11 years ago

Interesting perspective.  I found their estimates were accurate up until the most recent downturn in our market.  Now they are way off and consumers don't understand.

Posted by Tracy Santrock, Raleigh - Cary Realtor/Broker In Charge (Fonville Morisey/Santrock Realty Group, Inc. ) about 11 years ago

I have not found zillow pricing to be very accurate on our island, with our small numbers of transactions.

Aloha from Kauai...

Posted by Ronnie Margolis, Kauai Realtor - CDPE, ABR, RA - On Top of the Aloh (KW Kauai) about 11 years ago

Sara, did you know that if you looked up your own property on Zillow and you don't agree with the stats, you can go into it and manually change the price for everyone to see? so if you wanted to sell your home, go into the system months in advance and make your home seem to be worth more money. You can input that you have a 5 bedroom 3 bath , when in reality it's a legal 3 bedroom 2 bath home.

Posted by Sonny Kwan, 206-819-8228 (Quantum Group Commercial - Residential - Lease Seattle, WA ) about 11 years ago

It's difficult in areas where a home price is so dependent on the land value as in Hilton Head.  I haven't found Zillow to be that accurate here.

Posted by Diane Bell, Hilton Head Real Estate, Bluffton (Charter 1 Real Estate, Hilton Head, Bluffton, SC) about 11 years ago

Here we have found them to be way off either up or down. Our tax rolls have been known to be off by 50% or better. So other than our MLS I don't have a clue where they would get the info.

Posted by Charles Stallions, 800-309-3414 - Pensacola, Pace or Gulf Breeze, Fl. (Charles Stallions Real Estate Services ) about 11 years ago

Finally a margin a error to slay all of those Zillow slaves.  Thanks for the information.

Posted by Mike Henderson, HUD Home Hub - 303-949-5848 (Your complete source for buying HUD homes) about 11 years ago

Zillow gives an estimate when they know nothing about the house other than local sales- what if there was a nuclear power plant across the street? What if the house was in need of remdiation for toxic infestation? How about if there's something special about the property that does not show up in the tax records- like there is an additional structure on the premises like a barn or a studio for rent? Zillow is a joke with a pretty ribbon on it.

Posted by Peter Testa, PETER TESTA (Nationwide Homes) about 11 years ago

HI Sarah!
Thanks for the info..it is truly helpful, since in our area the homes are are older, unique and have been changed mulitple times since they were built. I am anxious to go on Zillow to see the accuracy table for our area. Thanks!

Posted by Paula Swayne, Realtor-Land Park, East Sac & Curtis Park -Dunniga (Dunnigan, Realtors, Sacramento (916) 425-9715) about 11 years ago

Hi Sara, we feel that Zillow is a great starting point and a tool for the consumer. But we have also found that many buyers believe that it is the accurate number the home is worth.

So for fun we just looked up our own personal property. We just had a appraisal done by Key bank. After the appraisal the lender shared with us that they are very conservative with their appraisals. The appraisal came in at $440,000.

Zillow today has our home today at $368,500.



Posted by Patty Carroll about 11 years ago

Wow! What a dynamite topic. I gather that you work for Zillow. My feelings about Zillow aren't positive, which I'm sure you all are not surprised by. But, I am glad to learn these facts about Zillow as it does exist and I can not ignore it when discussing prices with my clients.

I found the comment by Matt Stigliano, "Might be a good idea to have one of these printed out on a listing presentation to handle the 'But Zillow said...' statements," an excellent suggestion! That I will do.

Thank you Matt and Sara.

Posted by Marianne Snygg, ABR, ASP, GRI, SFR (ERA Herman Group Real Estate) about 11 years ago

They are a joke in many areas of Phoenix

Posted by Andrew Monaghan, CRS, GRI, EPro Associate Broker (The Monaghan Group) about 11 years ago

I haven't seen much information that is accurate for our area.  It's a useful tool in many ways but not always correct.

Posted by Bruce & Mary Smith, REALTORS, Savannah Lakes Village McCormick SC (Savannah Lakes Homes) about 11 years ago

Thanks for the post on Zillow.  Zillow estimates are not too accurate.  Give Zillow lots of credit for the work they are doing and they are a great data source  for home buyers and sellers beginning their research.  I have seen wildly variable number for Ann Arbor real estate.  Get information from experienced Realtors that know current market conditions.

Posted by Andy Piper (Ann Arobr real estate-Piperpartners.com) about 11 years ago

Hi Sara. Not sure if you remember me, but I was one of those agents who came up to you at the "Triple Play" real estate convention in Atlantic City, NJ and told you about my Zestimate gripe. Remember, I have the waterfront listing with panoramic views in South Amboy, NJ listed for $1,875,000 who has a buyer who wanted to make up his own price because "Zillow told him the home should be valued at lower price?" Thanks for turning me on the margin of error link on the site. I will definitely be using it going forward with buyers especially.

Posted by AMBER NOBLE GARLAND - Top Real Estate Expert, Property Tax Appeal Specialist & Author, - The Agent You Can Trust To Deliver REAL Results! (Strategic Marketing Expert & Relocation Specialist Serving New Jersey and nationwide!) about 11 years ago

Remeber that estimates are just that. Real estate is always a very localized affair and overall estimates never tell the whole story, but they are a place to start.

Posted by Brian Griffis (Realty Choice) about 11 years ago

I think the Zillow gives buyers or the sellers some ideas of their home value. However, at times with manhattan Real Estate market there are sometimes a huge gap in price difference... It may have to do with the fact that we do not have MLS here in New York city.

Posted by Eileen Hsu, LICENSED REAL ESTATE SALESPERSON (Douglas Elliman Real Estate) about 11 years ago

Sarah, Zillow is very close in this area. 

Posted by Tim and Pam Cash, Real Estate Professionals - Clarksville TN (Crye-Leike (Sango)) about 11 years ago

Hi Sara - I have checked zestimates of homes sold in my market area and find Zillow to be off by quite a bit.   When I look at comparable properties I'm finding the comps include active properties, withdrawn and expired properties, and some sold properties.  In my area Zillow reports a 10% + margin of error.

Posted by Jon Wnoroski, Summit County Realtor (America's 1st Choice RH Realty Co., Inc.) about 11 years ago

Zillow is total nonsense!  By the time you get the public records of closings your already how many days past?  That's not exactly what technology and the public is expecting is it?  Old info & not too accurate.  Yikes +/- 20%?

Posted by Lyn Sims, Schaumburg IL Real Estate (RE/MAX Suburban) about 11 years ago

I find Zillow to be accurate for very homogeneous properties for the area.  Basically are there a lot of similiar properties in similiar locations and similiar fit and finish.  Once you deviate from that there is no interpretation of the data and the Zillow numbers go askew.

Posted by Kevin Vitali, Helping Massachusetts Home Buyers and Home Sellers (EXIT Realty- Massachusetts Short Sales & Residential Sales) about 11 years ago

Spencer from Zillow here.

What a great discussion. Sara, thanks for the post. And thank you all for the comments.

I want to echo what several Realtors have pointed out: Zestimates are just a starting point, not the ending point in determining a home's value. That's all they're intended to be. Anyone who stubbornly believes that a home is worth exactly what a computer-generated Zestimate says, despite possible evidence to the contrary, is just plain wrong. There are of course many many homes where Zestimates are spot on, but there are also homes where the Zestimate is not even close. I'm going through a refi right now and my appraisal came within 0.1% of the Zestimate, both of which I think are pretty much spot on. So my house in Seattle seems to be pretty darn accurate, as is my in-law's place in LA and San Diego. But my parents' place in La Jolla.... oh don't get me started. My parents' never let a week pass without telling me that their Zestimate is too low.

We've always been very transparent about our accuracy statistics, as Sara points out. The accuracy chart is actually one of the most visited pages on our website, and with good reason. And the value range next to each Zestimate is important also.

The advice I'd give to a Realtor worried about an inaccurate Zestimate is to use it as an opportunity to show off how smart you are, at the expense of the computer algorithm. "Yeah yeah, that computer thing is all fine and good, but let me show you how my local market knowledge and specific understanding about your particular house can help us arrive at an even more accurate value of your home." In fact, many agent and brokerage websites actually choose to put Zestimate functionality onto their website for just this reason. They use it as a sort of light lead gen tool -- enter your address to get a Zestimate, and now if you want to talk to an agent about this please click here. Check out Prudential California's website, for example, or Southern Winds (a Charlotte brokerage).

As several of you pointed out, an owner or an agent can also "claim a home" and then publish their own estimate of the home's value. It's a little template wizard thingy where you can choose your own comps, add in your own home improvement information, etc, and it recalculates a value. You can then publish that to the site, if you want. In addition, you can change the home facts (e.g., # Beds, # baths, sqft, etc) and these changes actually affect the Zestimate itself. Millions of users (homeowners and agents) have done this. So if you have a listing and the Zestimate is troubling you, the best thing to do is to make sure that it's listed properly on the site, with the corrected home facts (which will improve the accuracy of the Zestimate). And if you want, to use the "My Estimator" tool to publish your own estimate of the home's value, or you can have the owner do it if you think it's sketchy for an agent to opine on a home's worth.

The most important thing to remember is that there are over 80 million homes listed on Zillow, almost every home in America. Unlike every other real estate website, we already have a webpage for pretty much every single home in the US. If it's posted for sale on Zillow (either via a brokerage feed or by an individual agent), then the Zestimate comes off of the map page entirely and it's replaced by the listing price, and the Zestimate gets bumped all the way to the bottom of the home's details page -- it's the For Sale price that's listed up top. So the advice I give to agents who think one of their listings has an inaccurate Zestimate is to make sure it's listed properly on Zillow, so the Zestimate gets bumped down and the gorgeous photos (of the home and of the listing agent, of course) are on the home's page. You can learn more about listings here.


Anyway, thanks everyone for the discussion. Something tells me this isn't the last time it will come up!


Happy New Year,


Posted by Spencer Rascoff (Zillow) about 11 years ago

A Zestimate would not be good to go by in my area.

Posted by Tony Anderson, Realtor - Serving Habersham Banks, White & Hall Co (Century 21 Community Realty) about 11 years ago

With all the emotional outpouing against Zestimate, Zillow must be on to something. :) I don't use Zestimate for valuations. I use it for price trends.

What Zillow is doing is the future of valuations. It is just a matter of time.

Banks don't use appriasals for valuations. They use them as justification for what they want to do anyway. If they don't want to do the loan, correct appraisal or incorrect appraisal, they will find something to reject the deal altogether.



Posted by Lee Ali (Las Americas Real Estate) almost 11 years ago

The real estate industry has thrived on hiding information from buyers. In the age of total disclosure of Facebook, Twitter, MySpace, etc., secretive MLS and even appraisals may be toast. It's just my guess.

There was a time when I used to wish that buyers, coming to see my listed properties, did not know about Zillow. At that time selling prices were higher than what Zillow would show. Zillow is a private company. In a free-market economy, they can present any information they want to present.

NAR seems to be very proud of being a seller-representing organization. Even in 2008, agent-assisted houses sold for 26% more money than a FSBO. http://www.realtor.org/research/commentary_falling_fsbo Isn't this "interesting" that real estate agents are so enamored with the word "SOLD," and not with "BOUGHT."

Real estate agents MUST understand that banks don't care about them when they show up as buyer agents. Heck, banks don't care about the buyers either. Bank of America is amusing itself with one of my buyers. :) They accepted an offer with a certain closing date. Since BofA has the price locked, they are now negotiating on the closing date even though I specifically told them that the client needs longer closing date.

Realtors will have to show respect to the all-empowered buyers, or...


Lee Ali is the author of "Crowdfunding: The Solution to Eliminate Booms and Busts in Real Estate Forever!”

Posted by Lee Ali (Las Americas Real Estate) almost 11 years ago

Sara, found this post when reading another on Coutrywide using Zillow. Thanks for the clarification about Zillow's sources and info on the accuracy. ~Sharon

Posted by Sharon Alters, Realtor - Homes for Sale Fleming Island FL (Coldwell Banker Vanguard Realty - 904-673-2308) almost 11 years ago

As an active real estate investor, I can say that Zestimates are normally completely ridiculous, particularly in areas that aren't totally homogenous.  Who knows what actually goes into the calculation, but my guess is it is the same inane "price per square foot proximate to other recent sales" model that got the US real estate market into all the trouble in the first place through inflated valuations.  Now the opposite is true--Zillow consistently underestimates the market price of homes in our area because of the number of distressed sales and low end housing that is close to very high end real estate.  How can Zillow account for quality of landscaping, flow of the house, utility, functionality, or just plain curb appeal.  Of course it can't.  I believe a good law firm should look into the efficacy of forcing Zillow to open up its calculation methods to the public, and not only that, perhaps Zillow should reimburse all the folks for its innaccuracies and undervaluations that are costing average homeowners tens of thousands of dollars when they go to sell their houses.  It's one thing to say in fine print that basically the Zestimate is irrelevant, but give me a break, every single buyer on earth--including me--uses that number to beat down the seller.  Zillow should be forced to at least explain its methodology and not just throw numbers out there.

Posted by Class Action over 10 years ago
Regardless of how accurate any of these websites are doesn't even matter. These are great tools but what really matters is FMV(fair market value). Definition(FMV): What a competent seller is willing to sell for, and what a competent buyer is willing to buy for. Plain an simple. That's fair. One time I bought a house for 250k when realtor and zillow comps said it was only worth 190k. Why would I do this? Because I knew I could sell it for 270k, and I did. 20k in the hip national bank. So be competent, and do your homework.
Posted by Corey Armstrong (re investor) about 9 years ago

Zillow estimates; My place vs next door. No upgrades or changes to either.

                       Mine       Next Door

   Year Built        1921     1910

   Sq Ft               912        826

Lot Sq Ft           3700       4000

    Date      Zillow estimates in thousands

Dec 1, 2006       $526       $539

Dec 1, 2007       $552       $534

Dec 1, 2008       $387       $421

Dec 1, 2009       $437       $417

Dec 1, 2010       $387       $389

Jan 1, 2011       $367       $494

Feb 1, 2011       $344       $551

Mar 1, 2011       $348       $567

Apr 1, 2011       $338        $577

May 1, 2011      $318        $579

Jun 1, 2011       $300        $414

2771 Dohr St, Berkeley, CA 94702

2769 Dohr St, Berkeley, CA 94702


Posted by Rusty Scalf over 8 years ago

I think it has been re-iterated that Zillow House Values or Zestimate is a starting point when you have a thought of putting your home on the market.  When it is time to get serious, it is time to call your local Realtor.    I recently did a post on the Zestimate accuracy and found in my community it was on average about 6.2% off leaving an average of $22,000 per home on the table.

Posted by Kevin Vitali, Helping Massachusetts Home Buyers and Home Sellers (EXIT Realty- Massachusetts Short Sales & Residential Sales) over 5 years ago

Information from the sites like Z. is based on a limited set of facts about a house, such as square footage an number of rooms. However, those AVMs may miss important factors, like  a desirable school district, view, noisy street exposure, privacy, etc. You have to compare the subject property to identical or similar and make all proper adjustments since rarely properties are the same( condition, location, layout, sqft, etc.)

Posted by Inna Ivchenko, Realtor® • Green • GRI • HAFA • PSC Calabasas CA (Barcode Properties) over 2 years ago