Online Bubble Level — Use Your Phone as a Spirit Level
No app needed · free in your browser

This page is a bubble level (spirit level) that runs in your phone's browser. There is nothing to install: open the page, tap the button, and the motion sensor built into your phone shows how far it is tilted left-right and front-back in real time.

When the blue bubble slides into the dashed circle in the middle, the display switches to "Level!". It is handy for everyday jobs such as hanging a shelf or a picture frame, checking that a TV or a table is level, or steadying a piece of furniture. It works in Safari on iPhone (iOS 13 or later) and in Chrome on Android.

Your phone's motion sensor is used to measure tilt in real time.
Nothing is sent to a server — everything stays in your browser.

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How to use this bubble level

Tap "Start the level".
On iPhone, a permission prompt for motion and orientation appears — choose "Allow".
Place the phone flat on the surface you want to check (a shelf, table, floor, and so on).
When the blue bubble sits inside the dashed circle, the display says "Level!".
The tilt is also shown as a number in degrees (°).

Readings are a guide only — sensor accuracy differs from phone to phone. Use a dedicated level when you need precision.

How to check whether your phone reads true

You can test your own phone in about a minute, without any tools:

Put the phone flat on a hard surface and note the two readings.
Turn the phone 180° on the same spot (so the top now points the other way) and note the readings again.
If the two readings are about the same, the sensor is reading true. If they differ by more than 1–2°, treat this level as a rough guide only, and use a real level for anything that matters.

Also remove the phone case if it is thick or uneven, and make sure the back of the phone and the surface are clean — a grain of grit can add a degree of tilt.

What you can use it for

Job	Tip
Shelves and cabinets	Put the phone on the shelf board and check the tilt
Picture frames	Hold the phone against the top edge of the frame
TVs and monitors	Hold the phone along the top of the screen or bezel
Furniture and desks	Lay it on the tabletop to find out why it wobbles
DIY projects	Place it on the material to check for level before you fix it
Moving and rearranging	Check the floor before you set up appliances or furniture

Frequently asked questions

Q. Do I need to install an app?

A. No. This is a web page: open it in Safari or Chrome and tap Start. There is nothing to download or sign up for.

Q. Does it work on iPhone?

A. Yes, on iOS 13 and later in Safari. Tap Start and allow motion & orientation access when the permission prompt appears.

Q. Does it work on Android?

A. Yes. Chrome and most other Android browsers support the device-orientation sensor, and many phones will not show a permission prompt at all.

Q. Is my sensor data sent anywhere?

A. No. All measurements are processed in your browser; nothing is sent to a server.

Q. How accurate is it?

A. It uses your phone's built-in motion sensor, which is typically good to about ±1–2°. It is fine for hanging a picture or checking a shelf; use a dedicated level for construction or anything that needs precision.