SAN FRANCISCO, April 15 — Browser fingerprinting, the practice of identifying users by combining dozens of technical signals from their browser and device, was detected on 78 percent of the websites in the Tranco list of top 10,000 most-visited sites, the Electronic Frontier Foundation said in a survey published Tuesday — up from 61 percent in the foundation’s 2024 measurement.

The foundation, which has tracked the prevalence of fingerprinting through its Cover Your Tracks tool and a series of biennial surveys since 2018, attributed the bulk of the increase to changes in the web-advertising stack following Google Chrome’s deprecation of third-party cookies, which the company completed in late 2025 after several delays.

“What we are seeing is what the privacy community warned about when the cookie-deprecation roadmap was set,” said Dr. Hesper Caraballo-Wright, a senior staff technologist at the Electronic Frontier Foundation, in an interview with Consumer Tech Wire. “Removing third-party cookies was a meaningful change for one set of trackers, but in the absence of equally aggressive limits on the underlying signal surface — the fingerprinting surface — the advertising stack has moved to the alternative within the same ecosystem.”

What the survey measured

The 2026 survey ran instrumented browser sessions against the Tranco top 10,000 sites between January and March, looking for known fingerprinting techniques including canvas drawing, WebGL renderer querying, audio-context fingerprinting, font enumeration, hardware-concurrency probing, and timing-based device profiling. A site was classified as performing fingerprinting if any of these techniques was detected within the first ninety seconds of page load, regardless of whether the technique was being used for advertising, fraud detection, or another purpose.

The foundation noted that many sites perform fingerprinting for legitimate fraud-prevention purposes, particularly in financial services, but said the survey was not designed to distinguish defensive from advertising-driven fingerprinting at the network level.

Browser response

Apple’s Safari and Mozilla’s Firefox both ship anti-fingerprinting countermeasures by default, including canvas-output randomization, font-list normalization, and capping the precision of device-timing APIs. Google Chrome introduced its Privacy Sandbox suite in 2024 but has been slower to add the kinds of API-surface restrictions that the EFF and other privacy groups have called for.

A Google spokesperson, in response to questions from Consumer Tech Wire, pointed to the company’s existing Privacy Sandbox documentation and said Chrome’s “long-term roadmap continues to include reducing the entropy available to fingerprinting scripts.”

“The browsers that are doing the work — Safari, Firefox, the Tor Browser — show that the technical interventions are available,” said Dr. Caraballo-Wright. “The reason fingerprinting is at 78 percent is not that the countermeasures do not exist. It is that the dominant browser has not shipped them in a way that meaningfully changes the deployed stack.”

The Electronic Frontier Foundation said it will publish browser-by-browser anti-fingerprinting effectiveness scores in a follow-up report in June.

Reginald Rosenberg-Vance is editor in chief of Consumer Tech Wire.