extendTraces slow for chart with a lot of data


I have a page with three charts in it. All of them have about 50000 points. I am using scattergl and dates (YYYY-MM-DD HH:mm:ss) for X axis. These charts are updated every second. I am using extendTraces to do that. So each second I am calling extendTracess with a new dot and last parameter 50000 so I have only 50000 points on the chart.

Problem is that all mouse movements and hovers are very very slow. If I stop updating charts then everything is fast again.

Is there a faster way than extentTraces to do what I want?


Here is a fiddle that shows what I am talking about: https://jsfiddle.net/8e3hw2p0/1/
In my case slowness is even worse.


@mkevac We’re in the last stages of a scattergl upgrade here:


I believe that improved hover picking speed will be part of this. Until then I don’t believe there is much that can be done to speed up hover in scattergl.