Display Refresh Rate and Reaction Time
A higher refresh rate can shrink display lag, but the clock still includes your device—test the same way before and after a screen change.
Refresh rate, in hertz, is how often the panel draws a new frame. Display lag is the wait until that frame is actually visible. A higher rate can shorten the wait for the next picture of lights out. It does not remove your tap, the browser, or the rest of the device. This page explains that split. It does not diagnose health.
What Hz changes
A 60 Hz panel can start a new frame about every 16.7 ms. A 120 Hz panel can start one about every 8.3 ms. If lights out is ready just after a refresh, you may wait nearly one full frame before it appears. That slice is shorter when the panel refreshes more often.
Hz is not the whole display lag. Pixel response and picture processing can add time the Hz number does not show. A panel sold as 144 Hz can still be running at 60 Hz if the cable, the port, or the OS mode is limited.
- Frame interval. About 16.7 ms at 60 Hz, and about 8.3 ms at 120 Hz. That is the longest you might wait for the next paint of lights out.
- Display lag. The wait from the page deciding the lights are out until you can see that. Hz can shrink one part of that wait.
- Not the decision. The clock still includes the screen and the input path. A lower number after a screen change can be less lag.
- Same test. Keep the browser, the input, and a short session the same before and after you change the screen.
Refresh rate is not the whole device
The number you see also includes the mouse, touch, or keyboard, and the browser. A higher refresh rate can shrink display lag. It does not replace a slow input path.
Display lag plus the path from your tap is covered in device latency and reaction time. Read that before you treat a screen swap as the whole story. Test the same way before and after the change.
How to check the active rate
Open the OS display settings and read the active refresh rate, not only the number on the monitor box. A high-Hz panel left at 60 Hz still draws like 60 Hz.
A variable refresh mode changes the interval as the frame rate changes. For a lights-out comparison, a fixed rate is easier to read. Note the rate, then run the same short drill.
A TV that processes the picture can hold a frame longer than a monitor at the same Hz. This page will not guess that extra lag. If the number moves after you turn processing down, the screen path changed. The decision time may not have.
Compare before and after a screen change
Run a short scored set on the old screen, then the same set on the new one. Same browser. Same input if you can. One session does not prove the panel. A warmer start or a different mouse can move the number by as much as a refresh step.
Keep the scored set short. A long grind records tired taps. The warm-up before a scored set is on reaction time warm-up and progress.
how this tool measures a start covers the clock, so the number you track is the tap after lights out. Habits around practice are in how to improve reaction time.
