Provided by: kitty_0.32.2-1ubuntu0.4_amd64 
Name
kitten-diff - Pretty, side-by-side diffing of files and images
A fast side-by-side diff tool with syntax highlighting and images
Major features
• Displays diffs side-by-side in the kitty terminal
• Does syntax highlighting of the displayed diffs, asynchronously, for maximum speed
• Displays images as well as text diffs, even over SSH
• Does recursive directory diffing
Screenshot, showing a sample diff (images not supported)
Installation
Simply install kitty.
Usage
In the kitty terminal, run:
kitten diff file1 file2
to see the diff between file1 and file2.
Create an alias in your shell's startup file to shorten the command, for example:
alias d="kitten diff"
Now all you need to do to diff two files is:
d file1 file2
You can also pass directories instead of files to see the recursive diff of the directory contents.
Keyboard controls
┌─────────────────────────────┬─────────────┐
│ Action │ Shortcut │
├─────────────────────────────┼─────────────┤
│ Quit │ Q, Esc │
├─────────────────────────────┼─────────────┤
│ Scroll line up │ K, Up │
├─────────────────────────────┼─────────────┤
│ Scroll line down │ J, Down │
├─────────────────────────────┼─────────────┤
│ Scroll page up │ PgUp │
├─────────────────────────────┼─────────────┤
│ Scroll page down │ PgDn │
├─────────────────────────────┼─────────────┤
│ Scroll to top │ Home │
├─────────────────────────────┼─────────────┤
│ Scroll to bottom │ End │
├─────────────────────────────┼─────────────┤
│ Scroll to next page │ Space, PgDn │
├─────────────────────────────┼─────────────┤
│ Scroll to previous page │ PgUp │
├─────────────────────────────┼─────────────┤
│ Scroll to next change │ N │
├─────────────────────────────┼─────────────┤
│ Scroll to previous change │ P │
├─────────────────────────────┼─────────────┤
│ Increase lines of context │ + │
├─────────────────────────────┼─────────────┤
│ Decrease lines of context │ - │
├─────────────────────────────┼─────────────┤
│ All lines of context │ A │
├─────────────────────────────┼─────────────┤
│ Restore default context │ = │
├─────────────────────────────┼─────────────┤
│ Search forwards │ / │
├─────────────────────────────┼─────────────┤
│ Search backwards │ ? │
├─────────────────────────────┼─────────────┤
│ Clear search │ Esc │
├─────────────────────────────┼─────────────┤
│ Scroll to next match │ >, . │
├─────────────────────────────┼─────────────┤
│ Scroll to previous match │ <, , │
├─────────────────────────────┼─────────────┤
│ Copy selection to clipboard │ y │
├─────────────────────────────┼─────────────┤
│ Copy selection or exit │ Ctrl+C │
└─────────────────────────────┴─────────────┘
Integrating with git
Add the following to ~/.gitconfig:
[diff]
tool = kitty
guitool = kitty.gui
[difftool]
prompt = false
trustExitCode = true
[difftool "kitty"]
cmd = kitten diff $LOCAL $REMOTE
[difftool "kitty.gui"]
cmd = kitten diff $LOCAL $REMOTE
Now to use kitty-diff to view git diffs, you can simply do:
git difftool --no-symlinks --dir-diff
Once again, creating an alias for this command is useful.
Why does this work only in kitty?
The diff kitten makes use of various features that are kitty only, such as the kitty graphics protocol,
the extended keyboard protocol, etc. It also leverages terminal program infrastructure I created for all
of kitty's other kittens to reduce the amount of code needed (the entire implementation is under 3000
lines of code).
And fundamentally, it's kitty only because I wrote it for myself, and I am highly unlikely to use any
other terminals :)
Configuration
You can configure the colors used, keyboard shortcuts, the diff implementation, the default lines of
context, etc. by creating a diff.conf file in your kitty config folder. See below for the supported
configuration directives.
Diffing
syntax_aliases
syntax_aliases pyj:py pyi:py recipe:py
File extension aliases for syntax highlight. For example, to syntax highlight file.xyz as file.abc use a
setting of xyz:abc. Multiple aliases must be separated by spaces.
num_context_lines
num_context_lines 3
The number of lines of context to show around each change.
diff_cmd
diff_cmd auto
The diff command to use. Must contain the placeholder _CONTEXT_ which will be replaced by the number of
lines of context. A few special values are allowed: auto will automatically pick an available diff
implementation. builtin will use the anchored diff algorithm from the Go standard library. git will use
the git command to do the diffing. diff will use the diff command to do the diffing.
replace_tab_by
replace_tab_by \x20\x20\x20\x20
The string to replace tabs with. Default is to use four spaces.
ignore_name
A glob pattern that is matched against only the filename of files and directories. Matching files and
directories are ignored when scanning the filesystem to look for files to diff. Can be specified
multiple times to use multiple patterns. For example:
ignore_name .git
ignore_name *~
ignore_name *.pyc
Colors
pygments_style
pygments_style default
The pygments color scheme to use for syntax highlighting. See pygments builtin styles for a list of
schemes. Note that this does not change the colors used for diffing, only the colors used for syntax
highlighting. To change the general colors use the settings below.
foreground, background
foreground black
background white
Basic colors
title_fg, title_bg
title_fg black
title_bg white
Title colors
margin_bg, margin_fg
margin_bg #fafbfc
margin_fg #aaaaaa
Margin colors
removed_bg, highlight_removed_bg, removed_margin_bg
removed_bg #ffeef0
highlight_removed_bg #fdb8c0
removed_margin_bg #ffdce0
Removed text backgrounds
added_bg, highlight_added_bg, added_margin_bg
added_bg #e6ffed
highlight_added_bg #acf2bd
added_margin_bg #cdffd8
Added text backgrounds
filler_bg
filler_bg #fafbfc
Filler (empty) line background
margin_filler_bg
margin_filler_bg none
Filler (empty) line background in margins, defaults to the filler background
hunk_margin_bg, hunk_bg
hunk_margin_bg #dbedff
hunk_bg #f1f8ff
Hunk header colors
search_bg, search_fg, select_bg, select_fg
search_bg #444
search_fg white
select_bg #b4d5fe
select_fg black
Highlighting
Keyboard shortcuts
Quit
map q quit
map esc quit
Scroll down
map j scroll_by 1
map down scroll_by 1
Scroll up
map k scroll_by -1
map up scroll_by -1
Scroll to top
map home scroll_to start
Scroll to bottom
map end scroll_to end
Scroll to next page
map page_down scroll_to next-page
map space scroll_to next-page
Scroll to previous page
map page_up scroll_to prev-page
Scroll to next change
map n scroll_to next-change
Scroll to previous change
map p scroll_to prev-change
Show all context
map a change_context all
Show default context
map = change_context default
Increase context
map + change_context 5
Decrease context
map - change_context -5
Search forward
map / start_search regex forward
Search backward
map ? start_search regex backward
Scroll to next search match
map . scroll_to next-match
map > scroll_to next-match
Scroll to previous search match
map , scroll_to prev-match
map < scroll_to prev-match
Search forward (no regex)
map f start_search substring forward
Search backward (no regex)
map b start_search substring backward
Copy selection to clipboard
map y copy_to_clipboard
Copy selection to clipboard or exit if no selection is present
map ctrl+c copy_to_clipboard_or_exit
Source code for diff
The source code for this kitten is available on GitHub.
Command line interface
kitty +kitten diff [options] file_or_directory_left file_or_directory_right
Show a side-by-side diff of the specified files/directories. You can also use
ssh:hostname:remote-file-path to diff remote files.
Options
--context <CONTEXT>
Number of lines of context to show between changes. Negative values use the number set in
diff.conf. Default: -1
--config <CONFIG>
Specify a path to the configuration file(s) to use. All configuration files are merged onto the
builtin diff.conf, overriding the builtin values. This option can be specified multiple times to
read multiple configuration files in sequence, which are merged. Use the special value NONE to not
load any config file.
If this option is not specified, config files are searched for in the order:
$XDG_CONFIG_HOME/kitty/diff.conf, ~/.config/kitty/diff.conf, $XDG_CONFIG_DIRS/kitty/diff.conf. The
first one that exists is used as the config file.
If the environment variable KITTY_CONFIG_DIRECTORY is specified, that directory is always used and
the above searching does not happen.
If /etc/xdg/kitty/diff.conf exists, it is merged before (i.e. with lower priority) than any user
config files. It can be used to specify system-wide defaults for all users. You can use either -
or /dev/stdin to read the config from STDIN.
--override <OVERRIDE>, -o <OVERRIDE>
Override individual configuration options, can be specified multiple times. Syntax: name=value.
For example: -o background=gray
Sample diff.conf
You can download a sample diff.conf file with all default settings and comments describing each setting
by clicking: sample diff.conf.
Author
Kovid Goyal
Copyright
2025, Kovid Goyal
0.32.2 Jun 25, 2025 kitten-diff(1)