A syntax-highlighting pager for git and diff output

Delta brings language syntax highlighting, within-line insertion/deletion detection, and restructured diff output to git on the command line. Here's an example of git show output with git configured to use delta as its pager:

Features

	delta	git	diff-so-fancy	github/gitlab
language syntax highlighting	✅	❌	❌	✅
within-line insertion/deletion detection	✅	❌	✅	✅
multiple insertion/deletions detected per line	✅	❌	❌	✅
matching of unequal numbers of changed lines	✅	❌	❌	❌

In addition, delta handles traditional unified diff output.

Installation

Executables: Linux | MacOS | Windows | All

Homebrew:

brew install git-delta

FreeBSD pkg(8):

pkg install git-delta

Configure git to use delta

git config --global core.pager "delta --dark"  # --light for light terminal backgrounds

Alternatively, you can edit your .gitconfig directly. Delta accepts many command line options to alter colors and other details of the output. An example is

[core]
    pager = delta --dark --plus-color="#012800" --minus-color="#340001" --theme="base16-ocean.dark"

Windows

less.exe installed with git doesn't work well with delta. A patched version of less.exe and instructions for installing can be found here.

All git commands that display diff output should now display syntax-highlighted output. For example:

• git diff
• git show
• git log -p
• git stash show -p
• git reflog -p

Delta also handles unified diff output:

diff -u a.txt b.txt | delta

delta --dark (default)	delta --light

Supported languages and themes

To add new languages/color themes to delta, the process is

1. Clone the delta repo
2. Create new versions of the files assets/syntaxes.bin and/or assets/themes.bin. Please see the bat documentation for instructions on how to create new versions of these files. You will need to copy them into the assets/ directory of the delta git repo after creating them.
3. Recompile delta: cargo build --release
4. Now you have a new delta executable at target/release/delta that should feature your new language/theme (use --list-languages / --list-themes to check).

Delta does not currently support reading these files dynamically from ~/.config as bat does, but this is a feature that could be added.

24 bit color

Delta works best if your terminal application supports 24 bit colors. See https://gist.github.com/XVilka/8346728. For example, on MacOS, iTerm2 works but Terminal.app does not.

If you're using tmux, it's worth checking that 24 bit color is working correctly. For example, run a color test script like this one, or one of the others listed here. If you do not see smooth color gradients, see the discussion at tmux#696. The short version is you need something like this in your ~/.tmux.conf:

set -ga terminal-overrides ",xterm-256color:Tc"

and you may then need to quit tmux completely for it to take effect.

Mouse scrolling

If mouse scrolling is broken, try setting your BAT_PAGER environment variable to (at least) less -R . See issue #58 and bat README / "Using a different pager".

Options

Here's the output of delta --help. To use these options, add them to the delta command line in your .gitconfig file.

USAGE:
    delta [FLAGS] [OPTIONS]

FLAGS:
        --dark                      Use colors appropriate for a dark terminal background.  For more control, see
                                    --theme, --plus-color, and --minus-color.
    -h, --help                      Prints help information
        --highlight-removed         Apply syntax highlighting to removed lines. The default is to apply syntax
                                    highlighting to unchanged and new lines only.
        --light                     Use colors appropriate for a light terminal background. For more control, see
                                    --theme, --plus-color, and --minus-color.
        --list-languages            List supported languages and associated file extensions.
        --list-theme-names          List available syntax-highlighting color themes.
        --list-themes               List available syntax highlighting themes, each with an example of highlighted diff
                                    output. If diff output is supplied on standard input then this will be used for the
                                    demo. For example: `git show --color=always | delta --list-themes`.
        --show-background-colors    Show the command-line arguments (RGB hex codes) for the background colors that are
                                    in effect. The hex codes are displayed with their associated background color. This
                                    option can be combined with --light and --dark to view the background colors for
                                    those modes. It can also be used to experiment with different RGB hex codes by
                                    combining this option with --minus-color, --minus-emph-color, --plus-color, --plus-
                                    emph-color.
    -V, --version                   Prints version information

OPTIONS:
        --commit-style <commit_style>
            Formatting style for commit section of git output. Options are: plain, box. [default: plain]

        --file-style <file_style>
            Formatting style for file section of git output. Options are: plain, box, underline. [default: underline]

        --hunk-style <hunk_style>
            Formatting style for hunk section of git output. Options are: plain, box. [default: box]

        --max-line-distance <max_line_distance>
            The maximum distance between two lines for them to be inferred to be homologous. Homologous line pairs are
            highlighted according to the deletion and insertion operations transforming one into the other. [default:
            0.3]
        --minus-color <minus_color>                The background color (RGB hex) to use for removed lines.
        --minus-emph-color <minus_emph_color>
            The background color (RGB hex) to use for emphasized sections of removed lines.

        --plus-color <plus_color>                  The background color (RGB hex) to use for added lines.
        --plus-emph-color <plus_emph_color>
            The background color (RGB hex) to use for emphasized sections of added lines.

        --tabs <tab_width>
            The number of spaces to replace tab characters with. Use --tabs=0 to pass tab characters through directly,
            but note that in that case delta will calculate line widths assuming tabs occupy one character's width on
            the screen: if your terminal renders tabs as more than than one character wide then delta's output will look
            incorrect. [default: 4]
        --theme <theme>
            The syntax highlighting theme to use. Use --theme=none to disable syntax highlighting. If the theme is not
            set using this option, it will be taken from the BAT_THEME environment variable, if that contains a valid
            theme name. Use --list-themes and --compare-themes to view available themes. [env: BAT_THEME=]
    -w, --width <width>
            The width (in characters) of the background color highlighting. By default, the width is the current
            terminal width. Use --width=variable to apply background colors to the end of each line, without right
            padding to equal width.

Comparisons

delta vs. git
delta vs. diff-so-fancy
delta vs. github

Credit

https://github.com/trishume/syntect
https://github.com/sharkdp/bat
https://github.com/so-fancy/diff-so-fancy