diff2html-cli - Parse git diffs as JSON and generate pretty HTML.


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Diff to Html generates pretty HTML diffs from unified and git diff output in your terminal

Table of Contents


  • Unified diff and Git diff input

  • line-by-line and side-by-side diff

  • new and old line numbers

  • inserted and removed lines

  • GitHub like style

  • Code syntax highlight

  • Line similarity matching

Online Example

Go to Diff2HTML



npm install -g diff2html-cli


Usage: diff2html [ flags and/or options ] -- [git diff passthrough flags and options]

flag alias description choices default
-s --style Output style line, side line
--sc --synchronisedScroll Synchronised horizontal scroll true, false true
--hc --highlightCode Highlight code true, false true
--su --summary Show files summary closed, open, hidden closed
-d --diffStyle Diff style word, char word
--lm --matching Diff line matching type lines, words, none none
--lmt --matchWordsThreshold Diff line matching word threshold 0.25
--lmm --matchingMaxComparisons Diff line matching maximum line comparisons of a block of changes 2500
--diffMaxChanges Number of changed lines after which a file diff is deemed as too big and not displayed
--diffMaxLineLength Number of characters in a diff line after which a file diff is deemed as too big and not displayed
--renderNothingWhenEmpty Render nothing if the diff shows no change in its comparison false
--maxLineSizeInBlockForComparison Maximum number of characters of the bigger line in a block to apply comparison 200
--maxLineLengthHighlight Maximum number of characters in a line to apply highlight 10000
--hwt --htmlWrapperTemplate Path to custom template to be rendered when using the html output format [string]
-f --format Output format html, json html
-i --input Diff input source file, command, stdin command
-o --output Output destination preview, stdout preview
-u --diffy Upload to diffy.org browser, pbcopy, print
-F --file Send output to file (overrides output option) [string]
--ig --ignore Ignore particular files from the diff [string]
-v --version Show version number
-h --help Show help

Exit Status Codes

  • ๐ŸŽ‰ 0: Success
  • ๐Ÿ˜ต 1: Generic Error
  • ๐Ÿ˜ฐ 3: Input diff is empty
  • ๐Ÿ‘ฎ 4: Value of --hwt | --htmlWrapperTemplate is not a valid file

Custom HTML wrapper template

The template is a very based on a simple replace of several placeholders as coded https://github.com/rtfpessoa/diff2html-cli/blob/master/src/cli.ts#L40

To provide a custom template you need to make sure you have the following comments and imports in your HTML, exactly as they are here:

  • Inside the <head> tag
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.9.0/styles/github.min.css" />
  document.addEventListener('DOMContentLoaded', () => {
    const targetElement = document.getElementById('diff');
    const diff2htmlUi = new Diff2HtmlUI(targetElement);
  • Inside the <body> tag
<div id="diff">


diff2html -s line -f html -d word -i command -o preview -- -M HEAD~1

  • diff last commit, line by line, word comparison between lines, previewed in the browser and input from git diff command

diff2html -i file -- my-file-diff.diff

  • reading the input from a file

diff -u file1.txt file2.txt | diff2html -i stdin

  • reading diff from stdin

diff2html -f json -o stdout -- -M HEAD~1

  • print json format to stdout

diff2html -F my-pretty-diff.html -- -M HEAD~1

  • print to file

diff2html -F my-pretty-diff.html --hwt my-custom-template.html -- -M HEAD~1

  • print to file using custom markup templates can include the following variables

diff2html --ig package-lock.json --ig yarn.lock

  • Ignore package-lock.json and yarn.lock from the generated diff

NOTE: notice the -- in the examples


This is a developer friendly project, all the contributions are welcome. To contribute just send a pull request with your changes following the guidelines described in CONTRIBUTING.md. I will try to review them as soon as possible.


Make some changes, yarn build and then ./bin/diff2html ๐Ÿ˜‰


Copyright 2014-present Rodrigo Fernandes. Released under the terms of the MIT license.


This project is inspired in pretty-diff by Scott Gonzรกlez.

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Mar 30, 2022