AliExpress Accused of Using Inaudible Audio to Fingerprint Users

The developer, who uses the handle “laserphile,” said the discovery began when Bluetooth headphones connected to both his phone and PC kept losing audio from the phone shortly after he loaded the AliExpress homepage. Closing the tab fixed the issue immediately. Muting the tab, Firefox, or Windows did not help, and no visible media was playing on the page.

Laserphile's investigation showed that Alibaba, which operates AliExpress, had been using the WebAudio API to run invisible sound waves at zero volume. By measuring tiny differences in how each PC's hardware processed the signals, the site generated a digital fingerprint and sent it to Alibaba's telemetry servers. The same secret audio path also interfered with Bluetooth connections while scripts collected hardware memory, screen dimensions, and network data in the background.

Further inspection found additional fingerprinting techniques on the same site, including canvas, WebGL, hardware specs, WebRTC, mouse and touch events, and automation indicators. Together these signals formed a broad device profile for tracking.

For users who want to avoid this type of fingerprinting, the report recommends privacy-focused browsers such as Firefox or Brave, which can limit or block the technique. Brave additionally randomizes fingerprint data and blocks the AliExpress tracking scripts involved.