Zillow Seeks to Move CoStar Copyright Case to Seattle

Zillow, the online real estate marketplace giant, has filed a motion in federal court to transfer CoStar’s copyright infringement lawsuit from New York to the Western District of Washington. The motion, submitted earlier this month, asserts that the Seattle-based company believes the case has little connection to New York and was filed there by CoStar in a strategic move to gain legal advantage.

The case is shaping up to be one of the most closely watched legal disputes in the real estate tech world, with implications for how digital property listings are created, shared, and protected under copyright law.

Zillow Seeks to Move CoStar Copyright Case to Seattle

The Dispute: Zillow vs. CoStar

The legal battle began when CoStar Group, a major commercial real estate information and analytics firm and the parent company of listing platforms such as Apartments.com and LoopNet, filed a lawsuit in the Southern District of New York. In the suit, CoStar accuses Zillow of unlawfully using copyrighted listing photos and proprietary data that it claims are protected intellectual property.

CoStar has built its business on providing verified, proprietary real estate data, and it zealously guards the photos and listings it claims as its own. The company alleges that Zillow, in its bid to expand and stay competitive in the crowded online real estate market, used photos and other data originating from CoStar’s platforms without proper authorization.

Zillow, however, strongly disputes these claims. In its latest filing, Zillow not only denied any wrongdoing but also questioned CoStar's choice of venue for the lawsuit. According to Zillow’s legal team, the case has no significant ties to New York, and filing it there is nothing more than a forum shopping tactic.

Seattle: The “Proper and Convenient” Venue

Zillow is headquartered in Seattle, Washington, where most of its employees, systems, and relevant documentation are based. In the motion to transfer, the company argues that trying the case in New York would be inefficient and burdensome, especially given that nearly all operational decisions and technical implementations related to the alleged copyright infringement occurred in Seattle.

“CoStar’s decision to file this case in New York appears calculated to create an unfair advantage,” Zillow stated in the court filing. “The appropriate venue is where the relevant parties, witnesses, and records are located—namely, the Western District of Washington.”

Zillow’s legal argument leans on the principle that a case should be tried where the majority of relevant actions took place or where the defendant is based. By filing in New York, CoStar, which is headquartered in Washington, D.C., may be attempting to increase the complexity and cost of the case for Zillow, critics argue.

Broader Industry Implications

While this legal wrangling may appear to be just another case of corporate litigation, it comes at a pivotal time for the online real estate industry. The competition among platforms like Zillow, CoStar, Redfin, and Realtor.com is intensifying as more consumers turn to digital services to buy, sell, and rent homes. Data ownership, image rights, and listing control have become central issues in this digital transformation.

CoStar has a reputation for aggressively enforcing its intellectual property rights. In previous cases, the company has pursued firms and individuals for using its copyrighted photos or data without a license. Zillow’s defense challenges not just the merits of this particular suit but also the broader claim that CoStar’s grip on listing content is as legally absolute as it asserts.

If the case proceeds in Washington and Zillow’s defense gains traction, it could set a precedent that influences how real estate data and images are used across the industry. It could also open up conversations around fair use, licensing agreements, and the limits of copyright enforcement in digital marketplaces.

CoStar’s Strategy and Market Power

CoStar’s decision to go after Zillow is notable, especially considering the company's recent expansion efforts into residential real estate, traditionally Zillow’s stronghold. CoStar has spent billions acquiring residential platforms and has expressed ambitions to compete head-on with Zillow.

Some analysts see the lawsuit as not just a legal matter but a business strategy—an effort to slow down or undermine a major rival while asserting dominance over its growing database of listings and photos.

“This isn’t just about copyright—it’s about market positioning,” said a real estate technology analyst familiar with both companies. “If CoStar can establish that it owns and controls this data, it can create significant barriers for competitors like Zillow.”

What Comes Next

The court will now consider Zillow’s motion to transfer the case. If the judge agrees, the lawsuit will move to Seattle, which could shift the tone and strategy of the litigation. If the motion is denied, Zillow may have to fight the case in what it sees as an unfavorable and inconvenient venue.

In the meantime, both companies are continuing their core business operations, but with an added layer of tension. The outcome of this case could shape not only the future of Zillow and CoStar, but also the larger framework for how real estate information is regulated, shared, and monetized online.

As the real estate industry increasingly collides with big tech and digital media, legal skirmishes like this one are likely to become more frequent—and more complex.