# delta: a Syntax-Highlighted Pager for git diff > Stop squinting at raw git diff outputs. Learn how to install and configure Delta to add syntax highlighting and side-by-side views in under 5 minutes. ---  **TL;DR** `git diff` output is functional but hard to read: no syntax highlighting, no side-by-side view, line numbers buried in `@@ -47,6 +47,8 @@` noise. `delta` is a drop-in pager replacement that transforms every `git diff`, `git show`, and `git log -p` into a syntax-highlighted, side-by-side view with word-level diffs — with zero changes to your git commands. 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](/blog/ripgrep) (for `grep`) and [eza](/blog/linux-eza) (for `ls`). Outside a git repository, plain [`diff`](/blog/linux-diff-file-folder) remains the tool of choice.* ## Before and after ### A changed line without delta ```diff - 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](https://github.com/dandavison/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`. > **Why Docker first?:** > > The Dockerfile below installs `git` and `git-delta`, writes the full `.gitconfig` block from this > article, and pre-builds a tiny repo with exactly the kind of one-word change (`+ TOKEN_GRACE_MS`) > that makes delta's word-level diff worth seeing. Nothing changes on your own machine. **Dockerfile** ```docker FROM ubuntu:24.04 ENV DEBIAN_FRONTEND=noninteractive # Ubuntu's docker image only enables "main" + "restricted" by default; # git-delta lives in "universe". RUN sed -i 's/^Components: main restricted$/Components: main restricted universe multiverse/' \ /etc/apt/sources.list.d/ubuntu.sources && \ apt-get update && \ apt-get install -y --no-install-recommends \ git \ git-delta && \ rm -rf /var/lib/apt/lists/* # Configure git to use delta — the exact block from this article RUN git config --global core.pager delta && \ git config --global interactive.diffFilter "delta --color-only" && \ git config --global delta.navigate true && \ git config --global delta.side-by-side true && \ git config --global delta.line-numbers true && \ git config --global delta.syntax-theme "Dracula" && \ git config --global merge.conflictstyle diff3 && \ git config --global diff.colorMoved default && \ git config --global user.email "demo@example.com" && \ git config --global user.name "Demo" # Pre-build a repo with a real, word-level-diff-friendly change already # unstaged, so `git diff` has something worth looking at immediately RUN mkdir -p /root/demo && cd /root/demo && \ git init -q && \ printf 'function refreshToken(token) {\n const expiry = token.exp * 1000;\n return expiry;\n}\n' > auth.js && \ git add auth.js && \ git commit -q -m "Add refreshToken helper" && \ sed -i 's/const expiry = token.exp \* 1000;/const expiry = token.exp * 1000 + TOKEN_GRACE_MS;/' auth.js WORKDIR /root/demo # Signal clearly that this shell runs inside a container RUN echo "PS1='\n\e[0;33m🐳 \e[0;36m\$(whoami)\e[0m \w # '" >> /root/.bashrc CMD ["/bin/bash", "-i"] ``` Build and run it: ```bash $ 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 Prerequisite: git-delta ```bash $ sudo apt install git-delta ``` Verify: ```bash $ delta --version delta 0.18.2 ``` > **On older Ubuntu/Debian releases:** > > The package might be named `delta` rather than `git-delta`. If `apt install git-delta` fails, try `sudo apt install delta` — or install the latest binary from the [GitHub releases page](https://github.com/dandavison/delta/releases). ## Configure git to use delta Delta works as a `core.pager` replacement. Open your `~/.gitconfig` and add: ```ini [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. **Configuration reference** * **`core.pager = delta`** — tells git to pipe all paginated output through delta instead of `less`. This covers `git diff`, `git show`, `git log -p`, `git stash show -p`, and more. * **`interactive.diffFilter = delta --color-only`** — applies delta's color rendering inside interactive commands like `git add -p`, without breaking the input handling. * **`navigate = true`** — press `n` to jump to the next changed file, `N` to go back. Essential when reviewing a diff with many files. * **`side-by-side = true`** — displays the old and new versions in two columns. The single biggest readability improvement. * **`line-numbers = true`** — shows line numbers in a dedicated column on each side. No more parsing `@@ -47,6 +47,8 @@` headers. * **`syntax-theme = Dracula`** — sets the color theme for syntax highlighting. Change this to match your terminal's theme. Run `delta --list-syntax-themes` to see all options. * **`merge.conflictstyle = diff3`** — when combined with delta, shows all three versions during a merge conflict (ours, theirs, and the common ancestor). Much easier to resolve. ## 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: ```bash git -c delta.side-by-side=false diff ``` Or add a short alias to `.gitconfig`: ```ini [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: ```bash $ delta --list-syntax-themes ``` To preview a theme without changing your config: ```bash $ git diff | delta --syntax-theme=gruvbox-dark ``` Good starting points: **Theme picks by terminal background** * **Dark background** — `Dracula`, `gruvbox-dark`, `TwoDark`, `Nord` * **Light background** — `GitHub`, `Monokai Extended Light`, `OneHalfLight` ## Navigation between hunks With `navigate = true`, delta adds keyboard navigation inside the pager: **Navigation keys** * **n** — Jump to the next changed file * **N** — Jump to the previous changed file * **q** — Quit * **Space** — Page down 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: ```bash 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`](/blog/git-config), 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](https://github.com/jesseduffield/lazygit) and [tig](https://github.com/jonas/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`](/blog/git-config) is the natural next step — they inherit delta's rendering for free.