Help : DASH library / How to display the particulars of any point on a graph

Hi everybody, I would like to find a way to display the particulars of any point on a graph when pointing on it.

For instance with the graph below : I need to display the particulars of the black point on the top right :

  • either by drawing an horizontal line and a vertical line with the particulars
  • or by only displaying the particulars

(nb : the black point doesn’t belong to a list of data, but any zone of the graph)

Thanks a lot for your help !

I am still looking for a solution to this problem.
Has anyone been able to solve it yet?

Have you tried annotations or line shapes? Check out the examples on

Thanks Chris for your suggestion but I think it’s not the right feature.

I would like to draw a horizontal and vertical line according to the mouse cursor anywhere on the chart, not just at a data point on a trace.

Today, I cheat by having a transparent trace on my graph and by using the hover_data callback from the Graph object but it’s very slow if the graph contains many data points.


Ah I see - Perhaps the spike* properties would work: Single-Page Reference | Python | Plotly. Including spikesnap: 'data' to hover over the cursor

Thanks, unfortunately with spike option I need to keep my transparent trace on my graph.
I think it’s impossible to get the spike without having an hidden trace for the moment, isn’t it ?