LaTeX Differ

latex_differ.py creates a side-by-side PDF diff between two LaTeX sources. Each input can be a full project folder, a single .tex file, or a .zip archive. The script wraps latexdiff/latexmk, injects custom banners for floats, and restores key table tokens so that changes inside table, figure, algorithm, and similar environments are highlighted in place (cell-level edits, figure swaps, etc.).

Features

• Works on full LaTeX projects with nested folders: both input directories are copied intact to a temporary workspace so relative paths/graphics continue to resolve.
• Auto-detects the main .tex file (or accept --main) and calls latexdiff --flatten so multi-file projects are merged.
• Structural highlighter adds Updated Figure/Table/Algorithm banners and keeps table separators, ensuring float changes are called out where they actually render.
• Normal, deleted, and added text is rendered using the standard latexdiff blue/red markup while tables still compile cleanly thanks to selective reinsertion of %DIF commands.
• Uses latexmk (fallback to pdflatex) and copies the resulting diff.pdf to your chosen output path, with a locked-file fallback if the viewer keeps the file open.

Requirements

• Python 3.10+
• TeX Live (or another TeX distribution) providing latexdiff, latexmk, and pdflatex
• A shell environment that can run the above binaries on PATH

Usage

Basic command

python latex_differ.py path/to/old path/to/new -o diff.pdf

Each path/to/... may be:

• a directory containing a LaTeX project,
• a single .tex file (the script copies it into an isolated workspace),
• or a .zip archive (automatically extracted before diffing).

Common options

Flag	Description
--main path/to/main.tex	Relative path to the main file if auto-detect fails.
--latexdiff-arg "..."	Pass-through options to latexdiff (repeatable).
--no-default-latexdiff-args	Disable the built-in safety exclusions.
--engine {auto,latexmk,pdflatex}	Force a specific LaTeX build tool.
--keep-temp	Leave the temporary workspace on disk for debugging.
--verbose	Show all commands executed.

Example workflows

Diff two directories (explicit main file + verbose logging):

python latex_differ.py ./old ./new --main access.tex -o trustworthiness_diff.pdf --verbose

Diff two zipped projects:

python latex_differ.py old_version.zip new_version.zip -o diff.pdf

Diff two standalone .tex files:

python latex_differ.py paper_v1.tex paper_v2.tex

Output

• diff.pdf (or diff.locked.<timestamp>.pdf if the target is in use) written to the working directory.
• Temporary workspace printed when --keep-temp is set, useful if you want to inspect diff.tex or run LaTeX manually.

Notes

• Inputs are copied/extracted into a temporary workspace before diffing, so originals remain untouched. Large assets (figures, images, data) are duplicated temporarily—ensure sufficient disk space.
• The script automatically runs latexmk (or falls back to pdflatex + bibtex) on each staged project so that .bbl files exist and newly added references appear in the diff.
• This tool and its documentation were built with assistance from OpenAI Codex.