pdfdiff

Produces a PDF from two LaTeX sources with all changes marked in red — additions in red, deletions in red strikethrough.

Wraps latexdiff and handles the full build pipeline: bibliography generation, multi-file projects, and arXiv-style embedded .bbl files.

Usage

pdfdiff <original> <modified> <output-dir>

Each source can be:

Form	Example
Git branch name	main
.tex file path	paper/main.tex
Project directory	paper/

For directories and branches, the file containing \documentclass is used as the root automatically.

diff.tex and diff.pdf are written to <output-dir>.

Examples

# Compare two git branches
pdfdiff main feature-branch out/

# Compare two directories
pdfdiff paper-v1/ paper-v2/ out/

# Compare specific .tex files
pdfdiff old/main.tex new/main.tex out/

# Mix and match
pdfdiff main paper-v2/ out/

Requirements

Required:

• latexdiff — usually part of TeX Live / MiKTeX
• pdflatex
• git (for branch inputs)

Optional but recommended:

• latexpand — enables --flatten so \input/\include directives are inlined; ships with TeX Live
• bibtex / biber — required if the project has a bibliography

Installation

cargo install pdfdiff

How it works

1. Each source is resolved to a root .tex file (extracting git branches via git archive into a temp directory as needed).
2. The modified project is copied into <output-dir> so all relative asset paths work.
3. The modified source is pre-built (pdflatex + bibliography tool) to generate .bbl and other artifacts before the diff is compiled.
4. latexdiff produces diff.tex with change markup.
5. Red colour overrides are injected: both additions and deletions render in red (deletions get a strikethrough via \sout).
6. diff.tex is compiled twice with pdflatex to resolve cross-references.

arXiv projects

Projects that embed \input{main.bbl} instead of a live \bibliography{} call are handled automatically: a minimal .aux stub is written and bibtex is run to synthesise the missing .bbl before compilation.