Git Diff & Delta on Linux: Reading Code Changes Without GitHub Desktop

If you’ve stopped using GitHub Desktop and moved fully to the terminal on Linux 🐧, mastering git diff is non-negotiable.

git diff lets you inspect what changed, where, and how—directly from the command line 💻. Combined with Delta, it becomes clean, readable, and editor-like ✨—without any GUI.

📌 This article covers:

• 🔧 Git diff fundamentals
• 🧠 Commands you’ll use daily
• 🎨 Installing & configuring Delta
• ⚡ A clean terminal-based workflow

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🧠 1. What Is Git Diff (Delta)?

In Git, a diff (delta) represents the difference between two states of your code.

Conceptually, Git works in three layers:

📝 Working Directory → 📦 Staging Area → 🗄️ Repository (Commit)

git diff allows you to compare changes between any of these layers 🔍.

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🧪 2. Essential Git Diff Commands

🔹 2.1 View unstaged changes

git diff

Compares:

📝 Working Directory vs 📦 Staging Area

Use this to:

• 👀 Review code before staging
• 🐛 Catch mistakes early

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🔹 2.2 View staged changes

git diff --staged
# or
git diff --cached

Compares:

📦 Staging Area vs 🗄️ Last Commit

Perfect for double-checking before commit ✅.

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🔹 2.3 Diff a specific file

git diff app.py

Multiple files or directories:

git diff src/ tests/

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🔹 2.4 Diff between commits

git diff COMMIT_1 COMMIT_2

Example:

git diff HEAD~1 HEAD

🖥️ This replaces “Compare commits” in GitHub Desktop.

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🔹 2.5 Diff between branches 🌿

git diff main..feature/login

Or explicitly:

git diff main feature/login

Ideal for pre-merge reviews 🔎.

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🔹 2.6 Summary-only diffs

Only file names:

git diff --name-only

With status:

git diff --name-status

Example output:

M app.py
A auth.py
D old_utils.py

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🎨 3. Making Git Diff Readable with Delta

Default Git diff output can be painful to read 😵. Delta upgrades it with:

• 🌈 Syntax highlighting
• ↔️ Side-by-side view
• 🔢 Line numbers
• 🧭 Keyboard navigation

Once you try it, you’ll never go back 💯.

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📦 4. Installing Delta on Linux

🐧 Ubuntu / Debian

sudo apt install git-delta

🏹 Arch Linux

sudo pacman -S git-delta

🎩 Fedora

sudo dnf install git-delta

Verify installation:

delta --version

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⚙️ 5. Set Delta as the Default Diff Viewer

Enable Delta globally:

git config --global core.pager delta

Recommended settings ⭐:

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 delta.navigate true
git config --global delta.light false

🎉 Now every git diff looks beautiful.

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🧩 6. Recommended Git Configuration (Full Setup)

Edit global config:

git config --global --edit

Add:

[core]
    pager = delta

[interactive]
    diffFilter = delta --color-only

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

[diff]
    colorMoved = default

🧠 This feels like a modern code review tool—right in your terminal.

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🔄 7. Daily Git Workflow (No GUI Needed)

A clean, safe workflow 🛡️:

git status
git diff
git add .
git diff --staged
git commit -m "feat: add login validation"
git push

Check recent commits:

git log --oneline --graph --decorate -5

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⚡ 8. Useful Git Diff Aliases

Work faster with aliases 🏎️:

git config --global alias.d "diff"
git config --global alias.ds "diff --staged"
git config --global alias.dc "diff HEAD~1"

Usage:

git d
git ds
git dc

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🔁 9. GitHub Desktop vs Terminal

GitHub Desktop 🖱️	Terminal 💻
View Changes	git diff
Staged Changes	git diff --staged
History	git log
Compare Branches	git diff main..feature

Terminal workflows are faster, scriptable, and customizable 🚀.

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🧾 10. Bonus: Inspect a Commit Directly

Latest commit:

git show HEAD

Specific commit:

git show <commit-hash>

Includes diff + metadata 📌.

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🏁 Conclusion

If you:

• 🐧 Use Linux
• 💻 Love the terminal
• 🎯 Want full Git control

Then Git Diff + Delta is a must-have skill 💎.

Once set up, code reviews become:

• ⚡ Faster
• 🧼 Cleaner
• 🧠 More reliable than GUI tools