Real-time lux meter with graphs, history, and CSV export. Easy to read.
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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