Bubble Level
Check horizontal and vertical alignment using your phone's tilt sensors.
Use your device sensors
Best on a phone or tablet. Sensor readings stay on your device.
How to use your phone as a bubble level
- Enable sensors. Open the tool on a sensor-equipped phone or tablet and tap "Enable sensors."
- Read the level. Place the phone flat to center the circular bubble, or against an edge for horizontal/vertical angle readouts.
- Calibrate if needed. Tap "Set zero" to measure relative to the current surface, or "Reset zero" to return to the device baseline.
What happens to your sensor data
The level reads your device's tilt through the browser's deviceorientation API, entirely on your device — nothing is sent anywhere. iOS Safari requires a tap on "Enable sensors" to grant motion and orientation permission before it can start.
What this level supports
Common reasons to use this level
- Check if a shelf, picture frame or TV mount is level.
- Level a tripod, camera rig or workbench on an uneven surface.
- Verify a tabletop or appliance without carrying a separate tool.
- Do a quick tilt check while hanging art or installing a fixture.
Frequently asked questions
Is my sensor data uploaded anywhere?
No. All readings stay on your device.
Why won't sensors enable?
It needs HTTPS (or localhost) plus your browser's motion/orientation permission. Desktop computers usually have no orientation sensor, so a phone or tablet works best.
Why is my reading off even on a flat surface?
Remove a thick or uneven phone case for a more reliable physical reference, then tap "Set zero" to calibrate to your actual surface.
How precise is it?
Level indication is accurate to within about one degree — fine for everyday leveling tasks, but not calibrated measurement equipment.
Can I calibrate to a specific surface?
Yes — "Set zero" measures relative to whatever surface the phone is currently resting on.
Last reviewed: August 2026