AliExpress Tracks Users Through Headphones, Developer Discovers

A developer accidentally discovered that his Bluetooth headphones refused to switch from his computer to his phone while browsing the AliExpress website.

The company uses the WebAudio API to play invisible sound waves. By measuring how each device processes these signals, the site creates a unique digital fingerprint for tracking.

Data collection goes beyond audio. The same scripts measure other hardware parameters, including mouse movements, forming a complete device identifier sent to Alibaba servers.