Ambient Light Support Test
Report ambient light in lux where the sensor exists — and honestly say when it doesn’t, without fabricating values.
This feature isn’t available here
The Ambient Light Sensor isn’t available in this browser.
Why: Most browsers don’t expose it for privacy reasons, so we can’t report a lux value — and we won’t fake one.
Commonly supported by: Limited to some Chromium builds with sensor flags enabled.
What you can do: There’s no reliable browser fallback for measuring light. Use a dedicated app if you need lux readings.
How this test works
Mobile and sensor tests read the capabilities your device exposes to the browser. Motion and orientation come from the DeviceMotion/DeviceOrientation events or the newer Generic Sensor API (Accelerometer, Gyroscope), which stream readings many times per second.
On platforms that require it — notably iOS — we request explicit permission from a user tap before starting a motion or orientation sensor. Readings are throttled for a smooth chart and the stream is paused when the page is hidden.
We never invent values. When a sensor such as ambient light isn’t exposed, the test says so clearly rather than showing a fabricated number.
How to use it
- Open the test on a phone or tablet over HTTPS.
- Tap the enable button and allow motion/orientation access if prompted.
- Move, tilt or rotate your device and watch the live values or chart respond.
- For orientation lock or wake lock, use the provided buttons — they fail cleanly if not permitted.
- Stop the test to release the sensor when you are done.
What it detects
- Acceleration and angular velocity on the X, Y and Z axes
- Device orientation (alpha/beta/gamma) and an approximate compass heading
- Screen orientation type and angle, and change events
- Which mobile capabilities (vibration, battery, wake lock, sensors) are supported
What it can’t detect
- Sensors your device or browser doesn’t expose (support varies widely, especially on iOS)
- Calibrated, laboratory-grade sensor values
- Ambient light in lux where no sensor is available — we never fabricate it
Troubleshooting
| Symptom | What to do |
|---|---|
| Sensor says unsupported | Not every device or browser exposes every sensor; iOS in particular restricts some APIs. |
| Permission denied | Enable motion & orientation access in your browser’s site settings, then retry from a tap. |
| Compass seems wrong | Move away from magnets and metal and calibrate by moving the device in a figure-eight; browser headings are approximate. |
| Orientation won’t lock | Most browsers only allow orientation lock in full screen or an installed PWA. |
FAQ
Why does a sensor say unsupported?
Not every device or browser exposes every sensor. iOS in particular restricts some APIs.
Do you track my location or motion?
No. Sensor data is used only to drive the live display and never leaves your device.
Why ask permission?
Some platforms require explicit permission for motion and orientation sensors, which we request only on a tap.
Why is the compass approximate?
Only iOS exposes a true heading; elsewhere it’s derived from orientation and affected by magnetic interference.
Do these work on a laptop?
Some do, but most phones and tablets expose more sensors than laptops or desktops.
Does the sensor keep running in the background?
No. Readings pause when the page is hidden and stop when you leave or press Stop.