Lux Light Meter

Measure ambient light levels using your smartphone’s built-in light sensor.

Use it to check room brightness, evaluate lighting at your desk or workspace, monitor lighting conditions for plants, or get a rough reference for photography.

■ Key Features

- Real-time illuminance display

- Switch between lux (lx) and foot-candles (fc)

- View minimum, average, and maximum readings at a glance

- Graph changes in illuminance over time

* Save measurement history and export data as CSV

■ Recommended Illuminance Guide

- View recommended illuminance levels for different areas, including living rooms, bedrooms, computer workspaces, and kitchen countertops

- Set a target illuminance range and display upper and lower limits on the graph

- Automatically indicate whether the current level is "Appropriate", "Too Dark", or "Too Bright"

- Reference values are representative levels based on "EN 12464-1" and "JIS Z 9110"

■ History & Export

- Save the measurement start date and time, measurement duration, number of data points, and minimum / average / maximum values

- Filter and sort records by date

- Delete multiple records at once

- Export and share measurements as CSV files that can be opened in spreadsheet applications

* Add notes to measurement records

■ Settings

- Adjust readings using a correction factor and offset to match the readings of your existing illuminance meter

- Set the measurement interval from 0.2 seconds to 1 minute

- Enable or disable the always-on display

- Use a design optimized for both indoor and outdoor viewing, with optional dark mode

- Choose where CSV files and screenshots are saved

■ Important Notes

- Sensor performance and sensor location vary by device, so measurements should be considered approximate. For applications requiring accurate measurements, please use a calibrated illuminance meter.

- On many devices, the ambient light sensor is located near the top of the screen, close to the front-facing camera. Point the sensor toward the light source when taking measurements.

- This app cannot be used on devices without an ambient light sensor.

- Measurement data is stored loc