Device fingerprinting is a technique that identifies a specific physical device from hardware and software traits, such as GPU rendering behavior, installed fonts, and audio stack quirks, that persist across different browsers and cleared cookies. It's a more persistent identifier than browser fingerprinting alone, since it targets the underlying hardware rather than just the browser session.

Device fingerprinting is substantially harder to evade than IP- or browser-based checks, because it's harder to rotate than an IP address or a browser profile. A scraper can switch proxies and browser fingerprints per request, but replicating a fresh, plausible hardware fingerprint on every request is far more resource-intensive.

Because device fingerprints persist across browser sessions and even reinstalled apps on the same physical hardware, they're considerably harder for a scraper to rotate than an IP address or a browser-level fingerprint.