Refresh rate test
Phones sold with smooth 90 or 120 Hz screens are a favourite for copies, which often run at 60 Hz. This test counts how many times per second the browser draws the page.
Open this page on the phone you want to test. Press Back or the close button to stop at any time.
How to do it
- Turn battery saver off and set the screen to its highest refresh rate in Settings, Display.
- Tap Start and keep one finger moving on the screen while it measures (4 seconds).
- Compare the result with the refresh rate of the model the phone claims to be.
What the result means
- The same as the model's rate: the screen runs at the speed it should, at least in the browser.
- 60 Hz on a phone sold as 90 or 120 Hz: worth a closer look: check Settings, Display first, then test the phone with the Knowfone app.
- An odd number like 57 or 112: the browser was busy; measure again.
What a browser cannot see: whether the phone is really the model it claims (copies run on a different processor), how worn the battery is, whether the storage is as big as it says, and whether the system was modified. The free Knowfone app for Android checks all of that and every part above in about 7 minutes, then answers: good to buy, buy only at a lower price, or don't buy.
Questions
How do I check the refresh rate in settings?
Open Settings, Display. Samsung calls it Motion smoothness, Xiaomi and Redmi call it Refresh rate, Tecno and Infinix list it under Display as Screen refresh rate.
Is a 60 Hz result proof that a phone is a copy?
No. Battery saver, the refresh setting and some phones' power rules hold browsers at 60 Hz. It is a reason to check further, not proof. The Knowfone app also reads the screen's own modes and compares them with the model.
More phone tests
Buying a used phone? Read the 14-step checklist or look up the real specs of popular models.