Google deploys fingerprinting for ad targeting
Google began deploying fingerprinting technology on 16 February 2025 to allow advertisers to track users via device and browser characteristics. Regulators including the ICO and CNIL expressed concern that the technique reduces user control over data collection compared to cookies, since users cannot delete their digital fingerprint.
What happened
Since 16 February 2025, Google allows advertisers to use fingerprinting, a technique to identify users via device or browser characteristics.
Fingerprinting collects technical information such as screen size, operating system, timezone, browser type and IP address. Unlike cookies, users cannot delete their digital fingerprint or control how their information is collected.
Reported impact
Privacy advocates and regulators expressed concern that fingerprinting reduces user choice and control over data collection.
The ICO stated that fingerprinting is not a fair means of tracking users online and likely reduces people's choice and control over how their information is collected.
Index analysis
Google had previously opposed fingerprinting in 2019, declaring it an error that undermines user choice.
The CNIL noted that while fingerprinting is not prohibited by regulation, its use is regulated and requires clear user notification and consent.
Governance controls
Google stated it continues to give users the choice to receive or not receive personalized ads and would work with the industry to encourage responsible data use.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.