Layout background image is jamming from version 1.19.0

I have just noticed that changing from version _plotly-1.18.1.min.j_s to plotly-1.27.1.min.js has a jamming side effect. At pan, rendering is not smooth, the background image follows mouse cursor with significant delay. I tried several versions above 1.18.1 but all have the same negative effect. Interestingly the phenomena only occur loading images from local source, URL images behave nicely.
Maybe useful information:

  • all images are PNGs
  • side effect seems independent of image size
  • no error or warning messages can be seen in browsers console
  • behavior is tested in Firefox and Chrome

As the phenomena only occurs at locally loaded images I cannot create sample code.

Any idea what can cause this?

Can you share a reproducible example to help us debug?

How can I create a reproducible online example which loads image from local source (source: “images/test/wallpaper2you_476150.png” instead of URL)?

You can try uploading that image e.g. on

Hi etienne!

Sadly, I could not upload the image (only the html file content appeared after dropping the files), but the image URL in the code (line 49), so you can download it easily.
If you open the html in a browser (I prefer Firefox, Chrome does not allow loading image from local source due to CSFR), you can see the
jamming effect at image pan. Move comment from second line to third to use Plotly version 1.18.1. The jamming effect is gone.

I can’t replicate.

Can you share a screencast of the jamming you’re taking about?

I downloaded a screen record here:

I tested the phenomena on other machines too (both environment were Win10 64-bit Firefox).
You can see that clicking on pan and moving background image is jamming/clogging using latest or any Plotly version above 1.19.0.
In 1.18.1 the moving is smooth.