About ProtractorTool

Free online protractor · browser-only protractor tool

Why this project exists

People still need a quick way to measure an angle when a plastic protractor is missing—on a homework photo, a design screenshot, a DIY picture, or a PDF page capture. ProtractorTool is a focused online protractor that opens in the browser, stays free to use, and keeps image pixels on your device for the core tool workflow.

What the tool does

• Drag arms on a virtual protractor to read degrees (180° or 360° mode)
• Upload or paste images and screenshots as a background (screen protractor workflow)
• Optional angle snap, copy degrees, and PNG export
• Optional real-world scale so lengths can show in cm/mm/in/m after calibration
• Mobile loupe while dragging handles so fingers hide less of the vertex

What it does not do

• No account wall for basic measuring
• No server-side photo storage for angle calculation
• No claim of certified engineering or medical accuracy
• No sale of physical digital protractors (hardware shopping is a different intent)

How it works

ProtractorTool is a static website plus client-side canvas logic. Angle math uses browser geometry; images use local File and clipboard APIs. Hosting serves HTML, CSS, and JavaScript. Optional analytics, if enabled, only measure traffic.

Contact

Use the Feedback button in the header for bugs and ideas. For privacy or legal topics, mention that in your message.

Brand

ProtractorTool / protractortool.com — free online protractor tool.