Methodology
Each test labels its evidence as observed, browser-reported, estimated or user-confirmed. Every result page explains the browser API used and what that method cannot prove.
Four kinds of evidence
Observed means the test received a browser event or stream. Browser-reported means a value is supplied by a browser API and can be rounded or restricted. Estimated means a sample, such as animation timing, is used as an approximation. User-confirmed means you checked a visible pattern or heard a test sound yourself. None of these labels is a manufacturer certification.
Repeatable checks
Keep the same device, browser, connection and test settings when comparing results. Change one factor at a time, repeat the test and record whether the symptom changed. Close unrelated applications only when safe. For timing checks, keep the tab visible; background tabs and power-saving modes can change results.
Permissions and unsupported results
Camera and microphone checks require permission. A denied permission does not prove a hardware defect. A browser may not expose battery data, a gamepad or other capabilities even when the device works. Skip unavailable checks and compare with operating-system settings or the manufacturer's diagnostic tool before making a repair decision.
Reports
The report summarizes this run, including measurements, skipped checks and recommended next actions. Save a report before changing settings if you need a comparison. A PDF is a record of observations, not a warranty document or proof that every component is healthy.