After using Tare, place an object of known weight on the weighing surface and enter its weight.
A screen protector can affect capacitive contact and the reading. Perform the tare and precise calibration with the protector installed. Calibrate again after replacing or removing it; if touch is not detected reliably, the test will not work with that protector.
Pressure measurement requires Apple’s hardware 3D Touch sensor and Safari. Compatible models:
Compatible iPhone screens report relative touch force. The test converts that signal into an estimated weight and animates the weighing surface as pressure changes. The object must create a capacitive touch, either directly or through a suitable soft conductive holder. Ordinary plastic, glass and other insulating objects may not be detected.
“Tare” subtracts the current pressure, which is useful when a holder is already resting on the screen. Select the same Low, Medium or High sensitivity that is set in the iPhone’s 3D Touch settings. For a better estimate, open “Precise calibration”, tare the holder, place a reference object of known weight on the weighing surface, enter its weight in grams and tap “Calibrate”. Repeat calibration whenever the phone, screen protector, holder or touch conditions change.
This is an experimental browser tool, not a certified scale. Readings can vary with the iPhone model, touch sensitivity, position, contact area, screen protector and movement. Use the result only as an approximation. Do not use it for medicine, jewellery, cooking portions or any decision that needs an accurate measurement. Use only soft objects; hard, sharp, hot, wet or abrasive items can damage the screen.