A PDF comparison utility in Python.
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Finds differences between two PDF documents:

  1. Compares the text layers of two PDF documents and outputs the bounding boxes of changed text in JSON.
  2. Rasterizes the changed pages in the PDFs to a PNG and draws red outlines around changed text.

Example Image Output

The script is written in Python 3, and it relies on the pdftotext program.


libxml2 >= 2.7.0, libxslt >= 1.1.23, poppler

Requirements installation for Ubuntu:

sudo apt-get install python3-lxml poppler-utils

Requirements installation for OS X:

brew install libxml2 libxslt poppler


From PyPI:

pip install pdf-diff

From source:

sudo python3 setup.py install


Turn two PDFs into one large PNG image showing the differences:

pdf-diff before.pdf after.pdf > comparison_output.png