Why Track Tab Session Uptime and Page Duration?

When debugging real-time web connections, evaluating user engagement, or checking browser memory leakage under long-running tasks, knowing the exact duration a page has remained open is very useful. Session uptime measures this open duration from the initial page load event. Our browser-native Session Uptime Tracker monitors this navigation duration locally, showing detailed time elapsed, visibility state history, and active session properties. Check your tab connection at /devicelab/device-info/session-uptime-tracker.

Using performance.now() and Page Visibility APIs

Standard JS timers like setInterval can drift when the CPU is busy or the tab is backgrounded. To track exact duration, modern scripts use the Page Visibility API and `performance.now()`, which provides high-resolution time measurement unaffected by clock shifts.

How to Monitor Active Tab Uptime Locally

Go to /devicelab/device-info/session-uptime-tracker. The tool starts a high-precision session counter, showing active page time, count of tab switches (visibility checks), and peak memory levels. The metrics remain client-side in the browser.