I have asked this on thematplotlib-users mailing list (https://mail.python.org/pipermail/matplotlib-users/2018-July/001464.html) and I was encouraged to open an issue here.

Bug report

Bug summary

Animations created withto_jshtml() are centered, and it is quite hard to un-center them.

The culprit is this line:

Code for reproduction

An example can be seen on this page:https://splines.readthedocs.io/en/latest/bezier.html

Actual outcome

The HTML+JS animations are centered.

Expected outcome

Ideally, the alignment of animations should be the same as when usingto_html5_video() and the same as for normal plots.
In other words, the animations should be left-aligned.

If the previous behavior isn't supposed to be changed, it would be great to add an option that allows disabling the centered alignment.

Another reason to remove the alignment: the "align" attribute of "div" elements is "obsolete" and "deprecated" according tohttps://developer.mozilla.org/en-US/docs/Web/HTML/Element/div

Matplotlib version

• Matplotlib version: all versions since JSAnimation was included (Import JSAnimation into the animation module. (Fixes #4703) #4821), JSAnimation had the same problem before