Sequentially presented stimuli overlap offline but not online

I’m trying to make my experiment to work both online and offline and I ran up with this problem. I have a routine that starts with a fixation cross, it starts at 0ms and ends at 5ms. Then a line is presented from 5ms untill there is a key press.

Online this works fine, so the fixation cross disappear and then the line appears. At least as much as my eyes can tell. But offline the fixation cross is briefly still present after the line is presented.

So fat I fixed by adding .05 seconds to the start of the line, but I want to know if this is normal or am I missing an option to prevent this overlapping?

I assume you mean .5s not .5ms

Try counting in frames rather than seconds. Alternatively, you could try starting the line at .485s

Oh, yeah, I meant .5 seconds.

I saw in the source code and it says currently PsychoJS can’t check what is the frame rate of the computer. So I guess for now the best is to use frames offline and seconds online. Thanks anyway.