Why a passport instead of a screenshot
A screenshot proves one moment. A passport shows the direction: a DualSense whose left stick sat at 1.8% in March and reads 5.9% in September tells a repair desk more than any single number. Each entry keeps the lab, the browser, the connection and the exact metrics, so two measurements can be compared honestly.
What gets stored
- Device identity: the label you type, plus USB vendor and product ids when the browser exposes them (controllers through the Gamepad API, mice and keyboards through WebHID, phones through client hints).
- Measurements: only the summary numbers a lab shows — drift percentages, observed DPI, polling statistics, touch rate, sensor verdicts. Raw traces are never stored.
- Context: the tool that produced the value, the date, and a shortened browser string.
Evidence sheet
The sheet is plain text: device identity, every measurement in order, and a trend line for each metric. It ends with the same boundary the labs show — browser-observed, not a manufacturer certification — because an honest record is more persuasive than an inflated one.
Measurement boundary: the passport records what your browser observed. It cannot see firmware calibration, and a value taken over Bluetooth is not comparable with a wired one. Keep the connection type constant when you compare dates.
