Viewing Differences

The git diff command shows changes between commits, branches, or working directory.

Types of Diffs

Command	Compares
git diff	Working directory vs staging
git diff --staged	Staging vs last commit
git diff HEAD	Working directory vs last commit
git diff branch1 branch2	Two branches

Basic Diff

Reading Diff Output

diff --git a/file.txt b/file.txt
--- a/file.txt
+++ b/file.txt
@@ -1,3 +1,4 @@
 unchanged line
-removed line
+added line
 unchanged line
+new line at end

• --- indicates the old version
• +++ indicates the new version
• - lines were removed
• + lines were added
• Lines without prefix are unchanged

Diff Options

Word-Level Diff

git diff --word-diff

Stats Only

git diff --stat

Specific File

git diff -- filename.txt

Between Commits

git diff abc123 def456
git diff HEAD~3 HEAD

Comparing Branches

# What's in feature that's not in main
git diff main..feature

# What changed since branching
git diff main...feature

Visual Diff Tools

git difftool

Configure a visual diff tool:

git config --global diff.tool vscode
git config --global difftool.vscode.cmd 'code --wait --diff $LOCAL $REMOTE'

Exercise: View Changes

Run git diff to see any uncommitted changes: