<p>Select a camera and microphone. Quick checks report numeric metrics automatically. Watches keep metrics here for Save metrics; audio and video never upload.</p>
<div><label>Mode <selectid="observation-mode"title="Choose a short reported check or a long local continuity watch."><optionvalue="quick">2-minute check</option><optionvalue="watch">10-hour continuity watch · local metrics</option></select></label>
<pid="watch-help"hidden>Keep this page visible and the computer awake. One capture session, no recording or upload. Save metrics before closing the page. Gaps and silence alone do not prove audio loss.</p>
<labeltitle="Recognize externally supplied coded colors and tones. Reports a diagnostic processing-time estimate, not calibrated lip sync or latency."><inputid="paired-signal"type="checkbox"> Paired test signal</label>
<labeltitle="Optional browser-only A/V replay and download. Off by default. Cleared on the next test or page close. Recording uses extra browser resources and can affect timing; it does not establish calibrated sync. Limited to 3 minutes and 128 MiB."><inputid="record-review"type="checkbox"> Record for review</label>