git diff Command: Show Changes Between Commits

Every change in a Git repository can be inspected before it is staged or committed. The git diff command shows the exact lines that were added, removed, or modified — between your working directory, the staging area, and any two commits or branches.

This guide explains how to use git diff to review changes at every stage of your workflow.

Basic Usage #

Run git diff with no arguments to see all unstaged changes — differences between your working directory and the staging area:

git diff

diff --git a/app.py b/app.py
index 3b1a2c4..7d8e9f0 100644
--- a/app.py
+++ b/app.py
@@ -10,6 +10,7 @@ def main():
print("Starting app")
+ print("Debug mode enabled")
run()

Lines starting with + were added. Lines starting with - were removed. Lines with no prefix are context — unchanged lines shown for reference.

If nothing is shown, all changes are already staged or there are no changes at all.

Staged Changes #

To see changes that are staged and ready to commit, use --staged (or its synonym --cached):

git diff --staged

This compares the staging area against the last commit. It shows exactly what will go into the next commit.

git diff --cached

Both flags are equivalent. Use whichever you prefer.

Comparing Commits #

Pass two commit hashes to compare them directly:

git diff abc1234 def5678

To compare a commit against its parent, use the ^ suffix:

git diff HEAD^ HEAD

HEAD refers to the latest commit. HEAD^ is one commit before it. You can go further back with HEAD~2, HEAD~3, and so on.

To see what changed in the last commit:

git diff HEAD^ HEAD

Comparing Branches #

Use the same syntax to compare two branches:

git diff main feature-branch

This shows all differences between the tips of the two branches.

To see only what a branch adds relative to main — excluding changes already in main — use the three-dot notation:

git diff main...feature-branch

The three-dot form finds the common ancestor of both branches and diffs from there to the tip of feature-branch. This is the most useful form for reviewing a pull request before merging.

Comparing a Specific File #

To limit the diff to a single file, pass the path after --:

git diff -- path/to/file.py

The -- separator tells Git the argument is a file path, not a branch name. Combine it with commit references to compare a file across commits:

git diff HEAD~3 HEAD -- path/to/file.py

Summary with –stat #

To see a summary of which files changed and how many lines were added or removed — without the full diff — use --stat:

git diff --stat

 app.py | 3 +++
config.yml | 1 -
2 files changed, 3 insertions(+), 1 deletion(-)

This is useful for a quick overview before reviewing the full diff.

Word-Level Diff #

By default, git diff highlights changed lines. To highlight only the changed words within a line, use --word-diff:

git diff --word-diff

@@ -10,6 +10,6 @@ def main():
print("[-Starting-]{+Running+} app")

Removed words appear in [-brackets-] and added words in {+braces+}. This is especially useful for prose or configuration files where only part of a line changes.

Ignoring Whitespace #

To ignore whitespace-only changes, use -w:

git diff -w

Use -b to ignore changes in the amount of whitespace (but not all whitespace):

git diff -b

These options are useful when reviewing files that have been reformatted or indented differently.

Quick Reference #

For a printable quick reference, see the Git cheatsheet
.

FAQ #

What is the difference between git diff and git diff --staged?
git diff shows changes in your working directory that have not been staged yet. git diff --staged shows changes that have been staged with git add and are ready to commit. To see all changes — staged and unstaged combined — use git diff HEAD.

What does the three-dot ... notation do in git diff?
git diff main...feature finds the common ancestor of main and feature and shows the diff from that ancestor to the tip of feature. This isolates the changes that the feature branch introduces, ignoring any new commits in main since the branch was created. In git diff, the two-dot form is just another way to name the two revision endpoints, so git diff main..feature is effectively the same as git diff main feature.

How do I see only the file names that changed, not the full diff?
Use git diff --name-only. To include the change status (modified, added, deleted), use git diff --name-status instead.

How do I compare my local branch against the remote?
Fetch first to update remote-tracking refs, then diff against the updated remote branch. To see what your current branch changes relative to origin/main, use git fetch && git diff origin/main...HEAD. If you want a direct endpoint comparison instead, use git fetch && git diff origin/main HEAD. If you want a clearer overview of what git fetch changes compared with git pull, see our guide on git fetch vs git pull
.

Can I use git diff to generate a patch file?
Yes. Redirect the output to a file: git diff > changes.patch. Apply it on another machine with git apply changes.patch.

Conclusion #

git diff is the primary tool for reviewing changes before you stage or commit them. Use git diff for unstaged work, git diff --staged before committing, and git diff main...feature to review a branch before merging. For a history of committed changes, see the git log guide
, and for syncing remote changes safely, see git fetch vs git pull
.