Glossary
Terms used across our guides and research.
Short, plain-language definitions. Each term links to the comprehensive guide.
- Browser fingerprint
- A profile built from combined browser and device signals that can recognize a returning browser without cookies.Read about Browser fingerprint
- Canvas fingerprinting
- A technique that reads hidden canvas rendering output to derive a stable per-browser value.Read about Canvas fingerprinting
- Entropy
- A measure of how much a signal narrows down which browser it came from; higher-entropy signals are more identifying.
- Extension fingerprinting
- Inferring browser extensions from exposed resources or observable page behavior, then combining those observations for recognition or profiling.Read about Extension fingerprinting
- Global Device Identifier (GDID)
- A Microsoft identifier that persists across Windows updates and identifies one Windows installation across certain Microsoft services.Read about Global Device Identifier (GDID)
- JA3 / JA4
- Fingerprint formats derived from TLS Client Hello fields such as cipher suites and extension order.Read about JA3 / JA4
- Linkability
- The degree to which separate sessions, requests, or accounts can be connected to the same underlying person or browser.
- Observer model
- A description of which party (page script, server, network operator, and so on) can access a given signal.
- Sensor fingerprinting
- Identification or inference using stable hardware variation or time-series measurements from motion, audio, and environmental sensors.Read about Sensor fingerprinting
- TCP/IP fingerprinting
- Classifying a client from low-level packet and network-stack defaults, independent of the browser.Read about TCP/IP fingerprinting