Bubble Level Tool
Turn your phone or laptop into a spirit level with the DeviceOrientation API — live two-axis tilt in degrees with one-tap calibration. Free and fully on-device.
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What is Bubble Level Tool?
A Bubble Level Tool turns a phone or laptop with orientation sensors into a spirit level: it reads the DeviceOrientation API, shows the tilt of the surface in degrees on two axes with an animated bubble, and offers one-tap calibration to treat any position as level zero.
Key Benefits
- Check flatness of shelves, mounts and appliances anywhere
- Measure relative tilt between surfaces with calibration
- No extra app — runs in the browser and works offline
Common Use Cases
- •Hanging picture frames and mounting TVs level
- •Setting up tables, tripods, 3D printers and appliances
- •DIY construction and campervan or boat leveling checks
How to use your phone as a bubble level
- Place and start: Lay the phone flat on the surface you want to check and press Start sensor — grant motion permission if the browser asks.
- Calibrate if comparing: To compare against a reference surface, press Calibrate here while resting on the reference so it becomes level zero.
- Read the tilt: Watch the bubble and degree readouts on both axes; the status turns green and says Level! when both are within ±1°.
Key Features
- Live two-axis tilt readout in degrees via the DeviceOrientation API
- Animated bubble that tracks the device tilt visually
- One-tap calibration to mark any surface position as level zero
- Green level indicator within ±1° of flat
- iOS motion permission handling and fully on-device processing
Frequently Asked Questions
How accurate is a phone bubble level?
Most phone orientation sensors resolve about 0.1°, which is comparable to a hardware spirit level. Accuracy is best when the phone is bare or on a flat case and allowed to settle for a second.
What does calibration do?
Calibration stores the current tilt readings as zero. This is useful on surfaces that are not perfectly horizontal — you can measure relative tilt against a reference, exactly like zeroing a digital inclinometer.
Why does nothing move on my laptop?
Many laptops lack orientation sensors, and desktops never have them. If no tilt values appear after starting the sensor, your device probably does not expose the DeviceOrientation API with usable beta/gamma values.
Does the level work offline?
Yes. Once the page is loaded, all sensor reading and display happens locally; no network connection is required.