Aim for 45–55% relative humidity. Roughly 40–60% is tolerable, but under 40% risks cracks, sunken tops and sharp fret ends, while over 60% brings swelling, higher action and a duller tone. Solid-wood acoustics are the most sensitive.
You enter them yourself from a hygrometer in the room — a cheap one works fine. Nothing is measured automatically and nothing leaves your browser. The tracker just stores your readings and shows you the trend.
The target is the same for both. Solid-wood acoustics react fastest, so they're the ones to watch. Solidbody electrics are tougher, but their necks and fretboards still move with humidity, so 45–55% is a good goal for everything on the wall.
Yes. Every reading is saved privately in your own browser, so your history and trend are waiting when you come back. No account, nothing uploaded.
