Open this page on a phone and tilt it.
How to Use the Bubble Level
- Open the page on a phone and tap Enable Sensors (iOS may ask for permission).
- Lay the phone on a surface and watch the bubble.
- When the bubble sits in the center circle, the surface is level.
Desktop browsers usually have no tilt sensor, so the bubble stays centered — use a phone for real readings.
Frequently Asked Questions
How does the bubble level work?
On a phone, it reads the device's tilt sensors and moves the bubble. When the bubble sits in the center, the surface is level. On a desktop without sensors it shows a note instead.