Measuring tools

Measure noise levels in decibels using your device microphone. Free, private.

Lay the phone on an appliance’s cable and see whether current is flowing, and how much.

Point the camera at a lamp or a screen and read its flicker frequency, depth and risk level.

Put the phone near the road, listen, and read the speed of each vehicle that goes past.

How long your phone still knows which way it is pointing.

How tall is that, and how far away — with an error bar.

Find the gap, not just the draft.

Measure a color without the room changing the answer.

Five ways to read rotation speed: by sound, by a marker in the camera, by the phone's gyroscope, by screen strobe and by a printable strobe disc. Plus lamp flicker and PWM.

See your real speed from GPS: max, average, distance and track export. Check what your dashboard reads against true speed. No install.

Digital spirit level using your phone's sensors — 2D surface bubble, inclinometer, plumb line and camera AR with angle export.

Browser compass with true north corrected for declination, bearing hold, a sighting mode and an honest accuracy figure.

Online protractor with transparent overlay and photo measurement — mm calibration, multi-angle, PNG/PDF/JSON export. Handy for builders, carpenters and students.

Find the elevation at any point on a map, build a profile along a route and get the slope in percent and degrees. Coordinates next to the height.

Free online ruler in actual size. Calibrate to your screen and measure in cm, mm and inches — on screen or on a photo.

A digital inclinometer that reads tilt in degrees, percent, per-mille and roof pitch — plus a clinometer mode for the height of trees and buildings.

Press Start Camera to activate your camera. The tool will convert light levels into audio tones.