CoStar Group has filed a federal lawsuit against Zillow, alleging the unauthorized use of tens of thousands of copyrighted real estate photos.
The complaint, filed in the Southern District of New York, calls the infringement “widespread and systematic,” and claims Zillow’s actions could lead to over a billion dollars in damages.
Claims at a Glance
CoStar states this is “one of the largest, if not the largest, image infringement cases in history,” and claims the following:
- Number of Images Allegedly Infringed: 46,979
- Estimated Views: Over 250,000 displays
- Sites Involved: Zillow.com, Redfin, Realtor.com, Trulia, StreetEasy, HotPads, Out East
- CoStar’s Evidence: Images with visible CoStar star watermark appearing across multiple listings and platforms
- Legal Precedent: Zillow was previously found liable in a copyright case brought by VHT, Inc.
The Photo Library at Stake
CoStar, which owns Apartments.com, Homes.com, and LoopNet.com, claims to have built the world’s largest library of real estate photos, employing thousands of photographers and adding 2M+ new images annually.
Each copyrighted photo is registered and watermarked with CoStar’s star-shaped logo, a feature visible in many of the allegedly infringed images on Zillow.
According to CoStar, Zillow used these photos:
- To populate unclaimed “property pages” that prompt owners to advertise
- In active listings for multifamily rental properties
- To power features like Zestimates and personalized property recommendations
- And to syndicate listings across partner sites like Redfin and Realtor.com
The complaint includes examples of listings on Zillow. In these, the CoStar watermark is initially obscured in thumbnail view, but once clicked on, the expanded view shows the watermark.
These images were also syndicated on Redfin and Realtor.com, both labeled “Provided by Zillow,” according to the filing.
How CoStar Says Zillow Profited
Zillow’s alleged use of CoStar images contributed to growth in its multifamily rental listings, which expanded from 40,000 to 60,000 properties in a year. During that same time:
- Zillow’s rental revenue jumped 33% YoY (Q1 2025)
- Zillow claimed 2.2M active rental listings by Q1 2025 (compared to 1.9M as of December 31, 2024)
- Zillow entered exclusive syndication deals with Redfin and Realtor.com, becoming the sole provider of multifamily listings on all three sites
These syndication partnerships amplified the reach of listings allegedly populated with CoStar images.
Legal Action and What’s Next
Andy Florance, CoStar’s Founder and CEO, said:
“Zillow’s theft of tens of thousands of CoStar Group’s copyrighted photographs is nothing short of outrageous. Zillow is profiting from decades of CoStar Group work and the billions of dollars we have invested. Even worse, Zillow is magnifying its infringement on Redfin and Realtor.com. If these other sites do not immediately remove our images, we will have no choice but to sue them as well. We are committed to stopping this systematic infringement and holding the wrongdoers to account.”
CoStar is seeking:
- Permanent injunctive relief
- Statutory damages (potentially exceeding $1B)
- Destruction of infringing images from Zillow’s systems
- Possible further suits if Redfin and Realtor.com don’t remove infringing content
CoStar has signaled that Redfin and Realtor.com may also face legal action if the allegedly infringing images are not taken down.
We’ll continue to share developments as discovery unfolds. For more details, read the full complaint below:
