latexdiff is a Perl program that compares two LaTeX files and produces a third file in which additions and deletions are marked with commands such as \DIFadd and \DIFdel. After compiling that file, revisions appear underlined, struck through, or highlighted in color.

Do I need to install Perl or TeX Live to use this site?

You do not need Perl on your computer. This site runs latexdiff-so inside WebPerl (Perl compiled to WebAssembly) in your browser. You still need a LaTeX compiler such as pdfLaTeX, Overleaf, or TeX Live to typeset the downloaded diff.

Are my LaTeX files uploaded to a server?

No. Comparison runs entirely in the browser. The old and new sources never leave your device.

How do I compile the latexdiff output?

Save the output as a .tex file and compile it with pdfLaTeX. The default Underline style needs the color and ulem packages. Change-bar markup needs the changebar package.

latexdiff Online — Compare LaTeX Files in Your Browser

latexdiff Online

Compare two LaTeX files and get a compilable diff with \DIFadd / \DIFdel markup. This page runs latexdiff itself — the same Perl tool used with Overleaf and arXiv workflows — inside WebPerl. Nothing is uploaded; the diff is computed on your machine.

Old and new sources

Paste the old and new LaTeX sources, then run latexdiff.

Old TeX New TeX

Options

Markup Math Ignore preambles (for document fragments)

Diff output

About latexdiff Online

latexdiff Online is a free browser tool for comparing two LaTeX documents. It runs the real latexdiff program (the standalone latexdiff-so script by Frederik Tilmann) inside WebPerl, a WebAssembly build of Perl. You get the same revision markup that people use with Overleaf, Git, and arXiv submissions, without installing Perl.

What latexdiff does

latexdiff reads an old .tex file and a new one, then writes a third file in which changes are wrapped in commands such as \DIFaddbegin \DIFadd{…} \DIFaddend for additions and \DIFdelbegin \DIFdel{…} \DIFdelend for deletions. When you compile that file, added text is typically underlined in blue and deleted text is struck out in red (Underline style).

How to use this page

Paste the previous version into Old TeX and the revised version into New TeX.

Choose a markup style and, if you have fragile equations, set math markup to Coarse or Off.

Tick Ignore preambles if you are diffing body fragments without \documentclass.

Run latexdiff, then copy or download latexdiff.tex and compile it with pdfLaTeX or Overleaf.

Markup styles and math

Underline (default) uses wavy underlines and strikeout via the ulem and color packages. Color (CTAD) maps to latexdiff’s CTRADITIONAL style (colored additions and footnote-style deletions). Change bar puts a bar in the margin next to changed lines (needs changebar). Fine math markup can break complex align environments; Coarse or Off is safer for heavy equations.

Privacy

Comparison happens on your computer. Sources are not uploaded to a server. After the WebPerl engine has loaded, the tool can be used without sending your manuscript anywhere.

Related tools

The CTAN package also includes latexdiff-vc for Git, Subversion, and similar version control, and latexrevise to accept or reject markup. This site focuses on the core two-file comparison. For the full manual see the latexdiff GitHub repository and the Overleaf latexdiff guide.