Browser Performance Fingerprinting

Understanding Performance Metrics in Bot Detection

Performance metrics play a crucial role in distinguishing real browsers from automated tools. Here's how each metric contributes to bot detection:

• Protocol & Connection Patterns: Real browsers typically use modern protocols (HTTP/2, HTTP/3) and show consistent connection reuse patterns. Since HTTP/3 operates over UDP, traditional HTTP/SOCKS proxies cannot handle it, forcing a downgrade to HTTP/2. This makes protocol downgrade patterns (especially on CDN resources that support HTTP/3) a strong indicator of proxy usage in automation tools.
• DNS Resolution: Regular browsers maintain DNS caches and show predictable lookup patterns, whereas some bot frameworks may bypass or exhibit unusual DNS behavior.
• TCP/TLS Handshake Times: Native browsers demonstrate consistent handshake timing patterns influenced by the operating system's network stack. Automated tools might show abnormal timing or bypass certain handshake steps.
• Frame Timing & Stability: Real browsers running in graphical environments show natural frame timing variations, while headless browsers or automation tools may exhibit unnaturally perfect timing or completely missing frame metrics.

These metrics, when analyzed together, create a unique performance fingerprint that helps identify authentic browser environments versus automated tools.