How to use this tool
- 1Plug your phone into the charger you want to test.
- 2Leave it connected for a minute so the tool can read the battery rising.
- 3Read the charging rate in percent per minute and the estimated time to full.
- 4Try a different charger or cable and compare the numbers.
About this test
This test reads the Battery Status API and measures how fast your battery level climbs while plugged in, then converts that into a percent-per-minute rate and an estimated time to full. A slow rate can point to a weak charger, a worn cable, a dirty charging port or a battery that has aged.
Phones never expose exact watts or milliamp-hours to the browser, so treat the numbers as a relative signal for comparing chargers and cables rather than a certified measurement. For the clearest reading, avoid using the phone while it measures, since the screen and apps draw power that slows charging.
Privacy: this tool runs entirely in your browser. No image, audio or device data is recorded or sent to any server.
Frequently asked questions
Why is my phone charging slowly?
Common causes are a low-power charger or USB port, a damaged or thin cable, lint in the charging port, using the phone while charging, or an older battery. Compare a few chargers here to find the fastest combination.
Is the percentage per minute accurate?
It is a real measurement of how fast the level rises, but not a lab figure. Charging is faster at low battery and slows near 100%, so compare tests at similar battery levels.