Free Bubble Level
Turn your phone into a spirit level.
What is the Bubble Level?
Hanging a picture, levelling a shelf or checking a table wobble usually means digging out a spirit level you can never find. But the phone in your pocket already has the sensor for the job. This bubble level uses your device's motion sensor to show whether a surface is level or plumb — the bubble slides to the centre and turns green when you're true.
Everything is read on-device; nothing is uploaded.
Last updated: Aug 27, 2026
What does this tool do?
It reads your phone or tablet's tilt sensor and shows a familiar bubble that drifts off-centre when the device is tilted. Lay the device flat to check a horizontal surface, or stand it against something to check vertical (plumb). Numeric roll and pitch angles back up the bubble, and both turn green within a degree of level.
It's a quick, always-with-you stand-in for a physical spirit level.
Key features
Live bubble
Moves with your device's tilt in real time.
Level & plumb
Check horizontal or vertical surfaces.
Angle readout
Roll and pitch in degrees.
Green when true
Clear confirmation at level.
Private
Sensor readings stay on your device.
Example
Common use cases
- DIY & home — Level shelves, frames and furniture.
- Renters — Hang things straight without buying tools.
- Tradespeople — A quick backup level on the go.
- Photographers — Check a tripod or surface is flat.
- Campers & travellers — Level a stove or a van.
- Anyone — Check level without a spirit level.
Benefits
- The level you always have with you.
- Bubble plus exact angle readout.
- Works for both level and plumb.
- Free and private.
Tips
- Open it on a phone or tablet — most laptops and desktops have no tilt sensor.
- On iPhone you'll be asked to allow motion access; that's expected and nothing is uploaded.
- Rest the device on the surface rather than holding it, for a steadier, truer reading.
- Check your phone against a surface you know is flat first, so you know its zero point.
- For precision or professional work, confirm with a physical level — phone sensors drift a little.
Common mistakes to avoid
Trying it on a laptop
Fix: Use a phone or tablet; most computers lack the motion sensor this needs.
Denying motion access
Fix: Allow it when asked — without the sensor the level can't read tilt. Nothing is uploaded.
Holding the phone by hand
Fix: Rest it on the surface for a stable reading instead of holding it.
Assuming lab accuracy
Fix: It's great for everyday jobs; calibrate against a known-flat surface and confirm with a real level for precision.
How it works
- 1
Open it on a phone
Allow motion access if asked.
- 2
Rest it on a surface
Lay it flat or stand it upright.
- 3
Read the bubble
Centred and green means level.
Frequently asked questions
The level reads your device's tilt sensor, and some browsers (notably on iPhone) ask permission before a site can use it. Nothing is uploaded — the readings stay on your device.
Usually not — most computers have no tilt sensor. Open it on a phone or tablet, which do.
It's good for everyday jobs like hanging a picture. For precision work, calibrate against a surface you know is flat and confirm with a physical level.
The level reads your device's tilt sensor, and some browsers ask permission first. Nothing is uploaded — the readings stay on your device.
Usually not — most computers have no tilt sensor. Open it on a phone or tablet.
Good for everyday jobs like hanging a picture. For precision, calibrate against a known-flat surface and confirm with a physical level.
Yes — free, no sign-up.
Conclusion
Turn the phone in your pocket into a spirit level: the bubble centres and turns green when a surface is true, with exact angles to back it up. Rest it on the surface, allow motion access, and it handles everyday levelling — keep a real level for precision work.