Variability in math libraries used for browser audio once provided unique signatures when combined with CPU differences. After this "soundprinting" technique gained attention, Firefox implemented a fix in version 118, released in 2023. The browser began using its own unique math libraries instead of relying on OS-shipped ones. Tom Ritter, a Firefox developer and Tor Project volunteer, stated that moving to constant libraries reduced the entropy enough to stop the technique.

The method is also ineffective in Chrome, which ships with its own libraries, according to a Google spokesperson. Safari users are likely safe for similar reasons, though Apple did not immediately confirm this. Ali Express’ use of an obsolete fingerprinting method raises questions about why it persists. This is likely because the retailer employs more than a dozen other tracking techniques.

These additional methods include canvas rendering, WebGL renderer information, extensions, shader precision, audio oscillator output, screen dimensions, device pixel ratio, hardware concurrency, installed plugins, supported formats, WebRTC behavior, performance timing, and various input events. The web audio trick appears to be a leftover from years past that went unnoticed until now.