How WebGL fingerprinting works
A website runs JavaScript that creates a WebGL context, often in a hidden canvas. The script can inspect several graphics-related signals:
- GPU details: vendor and renderer names, when the browser exposes them.
- WebGL capabilities: supported extensions, texture limits and available features.
- Shader behavior: supported precision levels and graphics pipeline differences.
- Rendered pixels: small variations caused by the GPU, driver, browser and operating system.
The site combines these values into a hash or profile. That profile becomes one part of a broader browser fingerprint. It can support analytics, fraud checks and bot detection, but it isn’t proof of a person’s identity.
WebGL vs canvas fingerprinting
Both methods render graphics and inspect the result, but they use different browser graphics systems.
| WebGL fingerprinting | Canvas fingerprinting | |
|---|---|---|
| Graphics system | 2D and 3D, usually hardware-accelerated | Mainly Canvas 2D |
| Main signals | GPU, driver, shaders and extensions | Fonts, text rendering and rasterization |
| Hardware effect | Usually stronger | Usually less direct |
Sites often combine WebGL with canvas fingerprinting and other signals instead of relying on either method alone.
Why proxies don’t change it
A proxy changes the source IP address that a website sees. It doesn’t change your GPU, graphics driver or WebGL output. A site may therefore correlate requests that use different proxy IPs but present the same graphics fingerprint.
The reverse can also attract attention. If one browser session keeps the same cookies and headers while its graphics profile changes repeatedly, the signals don’t form a coherent client. IP rotation alone doesn’t make separate requests look like separate devices.
Privacy and responsible testing
Clearing a cookie doesn’t reset graphics hardware traits. Private browsing also may expose many of the same WebGL values. Privacy-focused browsers can reduce or standardize these signals, while disabling WebGL removes direct measurements but may break graphics-heavy sites.
If you operate a site, disclose fingerprinting where required, keep only the data you need and treat matches as risk signals rather than identity proof. When testing or collecting public data, use a supported browser, keep its configuration consistent and respect site terms, access controls and request limits.
FAQ
Is a WebGL fingerprint unique?
No. Several devices can produce the same fingerprint, and one device’s result can change after a browser, operating system or graphics driver update.
Does a proxy hide my WebGL fingerprint?
No. A proxy replaces the IP address visible to the website, but JavaScript still runs in your browser and can read its WebGL characteristics.
Can WebGL fingerprinting work without cookies?
Yes. It can produce a recognition signal without storing a cookie, though the match is probabilistic and may become less reliable when software or hardware changes.