Matplotlib creates visually identical, but binary different, PDF plots. This script compare two PDF files by converting them to an image and performing a pixel-wise diff. As a bonus, a diff image is created and can be shown on the console by the unicode-equivalent of ascii art :-D

pipx install git+https://github.com/jkbjh/pdf-pixel-diff.git

Add this to your git config (e.g., .git/config):

[diff "pixelpdf"]
	binary = true
	command = sh -c 'pdf-pixel-diff --exit0 --asciiart $0 $1'

and in your .gitattributes put:

*.pdf	diff=pixelpdf

python -m pdf_pixel_diff --asciiart --storediff diff.png tests/version1.pdf  tests/version2.pdf

creates the following difference image diff.png:

which converted to unicode and displayed on the console looks like this: