ABOUT US
Why we built a free online protractor.
Free Online Protractor started from a small, specific annoyance: needing to check an angle — a shelf bracket, a roof pitch, a picture frame — and finding that every "online protractor" search result was a static drawing you dragged a line across, measuring nothing real. The phone already sitting in a pocket has the motion sensors to do this properly. It just needed a page that used them well.
Who's behind it
This site is built and maintained by an independent developer, not a company or agency. That keeps the scope honest: one tool, done carefully, rather than a product roadmap built to justify a team. Bug reports and feature requests go straight to the person who wrote the code — see Contact us.
What guides the build
Useful on the first visit
No sign-up, no install, no tutorial. Open the page on a phone and you have a working protractor in seconds — that bar doesn’t move as the tool grows.
Private by default
Sensor mode reads motion data your browser already exposes and processes it on your device. Nothing is uploaded, logged, or sold. See the Privacy Policy for the full detail.
Honest about precision
A phone is a great everyday tool, not a certified instrument. The interface is written to never overstate what a browser and a motion sensor can promise.
Where it's headed
The core of the tool — sensor mode, manual mode, calibration — is stable and gets refined rather than rebuilt. Future work leans toward more measurement contexts (fixed reference angles, saved readings) without adding accounts or turning the page into something heavier than "open it and measure."
If Free Online Protractor was useful, saved you a trip for a physical protractor, or you spotted something worth fixing, get in touch. Real usage and feedback are what shape what gets built next.