If you're on your laptop, there's already a great tool for diffing PDF tools: <a href="https://github.com/vslavik/diff-pdf">https://github.com/vslavik/diff-pdf</a><p>It has a great 'view' mode which shows the two PDFs overlaid in different colors:<p><pre><code> diff-pdf --view a.pdf b.pdf
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I wanted something similar I could use on mobile, even if it's not as good as vslavik's tool. This is it.