What is the best way to compare two notebooks?

I have two quite large notebooks with minimal differences. To compare them, I currently put them side by side and compare with my eyes, which feels quite inefficient. What are better ways to do this?

I have done some searching but only found questions from 8/9 years ago, they didn’t work for me. In Mathmatica 12 I could not find a function like "Notebookdiff" and I also do not use Wolfram Workbench.