Insert text or move mouse in box below to test the lag / latency:
(Note, due to Javascript limitations, even set above at 0 milliseconds, the red box (and maybe the text) trails behind the real cursor at around 25-50 milliseconds.)
For more info, see this great video to show how even 10 milliseconds makes a big difference: https://www.youtube.com/watch?v=vOvQCPLkPt4 Thanks to zorndyuke, sdrmme and vither999 on Reddit for help with implementation