delta: a Syntax-Highlighted Pager for git diff

You've been staring at git diff output for thirty seconds trying to figure out what actually changed. The plus and minus lines blur together, every file looks the same shade of red and green, and the line numbers are buried in a header that takes conscious effort to parse.

delta fixes it in five minutes.

It joins the same family of modern rewrites as ripgrep (for grep) and eza (for ls). Outside a git repository, plain diff remains the tool of choice.

Before and after​

A changed line without delta​

-  const expiry = token.exp * 1000;
+  const expiry = token.exp * 1000 + TOKEN_GRACE_MS;

Everything is the same weight. You scan the entire line looking for the difference.

The same line with delta​

Delta highlights + TOKEN_GRACE_MS at the character level — the rest of the line stays dim. Your eye goes straight to the change, not to the unchanged context around it.

This word-level diff is especially valuable when:

• A variable was renamed (getUserById → findUserById)
• A string had a typo fixed
• A flag was added or removed from a long function call

Without word-level diff, each of those scenarios produces a fully-red removed line and a fully-green added line. With delta, only the changed word is highlighted.

What is delta?​

delta is a syntax-highlighting pager that sits between git and your terminal. It intercepts raw diff output and renders it with:

• Syntax highlighting per language — a TypeScript change looks like TypeScript, a YAML change looks like YAML
• Side-by-side view — old version on the left, new version on the right, aligned line by line
• Word-level diff — highlights the exact characters that changed within a line, not the entire line
• Line numbers — always visible, consistently aligned
• Navigation — jump between diff hunks with n and N

The key point: you don't change a single git command. You still type git diff, git show, git log -p. Delta intercepts the output automatically.

Seeing It in Action with Docker​

You've just read the "before" diff above. Here's a container where delta is already installed, configured, and pointed at a real, unstaged change — so you can see the "after" without touching your own .gitconfig.

Build and run it:

$ docker build -t delta-demo .
[+] Building 26.7s (8/8) FINISHED
✔ exporting to image
$ docker run --rm -it delta-demo
🐳 root ~/demo # git diff

git diff opens in side-by-side view, syntax-highlighted, with TOKEN_GRACE_MS picked out at the character level instead of the whole line turning green. Press q to close the pager, then try git log -p, git show HEAD, or edit auth.js yourself and diff again — the same config applies to every command.

Install​

$ sudo apt install git-delta

$ delta --version
delta 0.18.2

Configure git to use delta​

Delta works as a core.pager replacement. Open your ~/.gitconfig and add:

[core]
    pager = delta

[interactive]
    diffFilter = delta --color-only

[delta]
    navigate = true
    side-by-side = true
    line-numbers = true
    syntax-theme = Dracula

[merge]
    conflictstyle = diff3

[diff]
    colorMoved = default

Save the file. No shell restart required — the pager is invoked per-command.

Let's look at what each option does.

Side-by-side mode​

With side-by-side = true, delta splits each changed file into two columns:

• Left — the old version, with removed lines in red
• Right — the new version, with added lines in green
• Both — unchanged context lines are shown on both sides, aligned

For a renamed function called in ten places, you no longer read two interleaved streams of red and green. You read the before on the left and the after on the right, like a code review tool.

If your terminal is narrow and the two columns become cramped, you can toggle off side-by-side for a single command:

git -c delta.side-by-side=false diff

Or add a short alias to .gitconfig:

[alias]
    dw = -c delta.side-by-side=false diff

git dw gives you single-column mode; git diff keeps the default.

Themes​

Delta uses the same theme engine as bat and syntect. To list all available themes:

$ delta --list-syntax-themes

To preview a theme without changing your config:

$ git diff | delta --syntax-theme=gruvbox-dark

Good starting points:

Navigation between hunks​

With navigate = true, delta adds keyboard navigation inside the pager:

This is most useful with git log -p or git diff HEAD~10 where the diff spans many files.

Delta works everywhere git does​

Once core.pager = delta is set, delta applies to every git command that pages output:

git show HEAD           # last commit, with highlighting
git log -p              # full history with diffs
git stash show -p       # what's in a stash entry
git diff HEAD~3         # compare to 3 commits ago
git diff main...feature # compare branches

No extra flags. No wrapper functions. It just works.

Going further​

If you also use git diff aliases in your .gitconfig, those aliases automatically benefit from delta since the pager is applied at the output stage, not the command stage.

For an even richer TUI git experience, delta works as the diff renderer inside lazygit and tig — both TUI git clients that respect core.pager.

Conclusion​

Thirty seconds of squinting at a raw git diff was the whole problem — no syntax highlighting, no side-by-side, line numbers buried in @@ noise. delta fixes all three with an apt install and a handful of .gitconfig lines, and every git command you already know keeps working exactly as typed.

If you also work through history with aliases, configuring git diff aliases in .gitconfig is the natural next step — they inherit delta's rendering for free.