About OnlineRuler
OnlineRuler was built to solve the fundamental inaccuracy of traditional online ruler tools. By pairing procedural HTML5 High-DPI canvas rendering with hardware-specific calibration equations, OnlineRuler delivers verified, real-world 1:1 scale physical measurements on any device.
What Makes OnlineRuler Superior?
- 4-Edge Multitasking: Measure along top, bottom, left, and right screen borders independently or all at once.
- Floating 360° Ruler: Measure angled, diagonal, and irregular objects without tilting your device.
- 2D Screen Caliper Box: Measure rectangular objects placed flat on the glass and compute live square area.
- Multi-Standard Calibration: Calibrate with credit cards, ISO ID cards, coins, paper banknotes, or exact display diagonals.
- Delta Distance Computing: Automatic calculation of exact span between guide markers.
Zero Tracking & Privacy First
OnlineRuler runs 100% locally in your web browser. No measurements or calibration numbers are sent to external servers.