How can I see the changes in a Git commit?

When I do git diff COMMIT I see the changes between that commit and HEAD (as far as I know), but I would like to see the changes that were made by that single commit.

I haven't found any obvious options on diff / log that will give me that output.

To see the diff for a particular COMMIT hash, where COMMIT is the hash of the commit:

git diff COMMIT~ COMMIT will show you the difference between that COMMIT's ancestor and the COMMIT. See the man pages for git diff for details about the command and gitrevisions about the ~ notation and its friends.

Alternatively, git show COMMIT will do something very similar. (The commit's data, including its diff - but not for merge commits.) See the git show manpage.

(also git diff COMMIT will show you the difference between that COMMIT and the head.)

As mentioned in "Shorthand for diff of git commit with its parent?", you can also use git diff with:

git diff COMMIT^!

or

git diff-tree -p COMMIT

With git show, you would need (in order to focus on diff alone) to do:

git show --color --pretty=format:%b COMMIT

The COMMIT parameter is a commit-ish:

> A commit object or an object that can be recursively dereferenced to a commit object. The following are all commit-ishes: a commit object, a tag object that points to a commit object, a tag object that points to a tag object that points to a commit object, etc.

See gitrevision "SPECIFYING REVISIONS" to reference a commit-ish.
See also "What does tree-ish mean in Git?".

You can also try this easy way:

git show <COMMIT>

git show shows the changes made in the most recent commit. It is equivalent to git show HEAD.

git show HEAD~1 takes you back one commit.

I usually do:

git diff HEAD~1

To show the changes regarding the last commit. If you have more commits just increase the number 1 to how many commits diff you want to see.

Use:

git show <commit_sha>

This will show you just what's in that commit. You can do a range by just putting a space between the two commit SHA-1 hashes.

git show <beginning_sha> <ending_sha>

which is pretty helpful if you're rebasing often because your feature logs will all be in a row.

If you happen to want to look at the last 3 commits you can use the HEAD syntax

git show HEAD~3 HEAD

First get the commit ID using,

git log #to list all

Or

git log -p -1 #last one commit id

Copy commit id.

Now we use two methods to list changes from a specific commit,

Method 1:

git diff commit_id^! #commit id something like this 1c6a6000asad012

Method 2:

git show commit_id
For example: git show 1c6a600a

From the man page for git-diff(1):

git diff [options] [<commit>] [--] [<path>…]
git diff [options] --cached [<commit>] [--] [<path>…]
git diff [options] <commit> <commit> [--] [<path>…]
git diff [options] <blob> <blob>
git diff [options] [--no-index] [--] <path> <path>

Use the 3rd one in the middle:

git diff [options] <parent-commit> <commit>

Also from the same man page, at the bottom, in the Examples section:

$ git diff HEAD^ HEAD      <3>

> Compare the version before the last commit and the last commit.

Admittedly it's worded a little confusingly, it would be less confusing as

> Compare the most recent commit with the commit before it.

The following seems to do the job; I use it to show what has been brought in by a merge.

git whatchanged -m -n 1 -p <SHA-1 hash of merge commit>

Another possibility:

git log -p COMMIT -1

For me this works just fine

git show COMMIT --compact-summary

Which shows the next information

> Output a condensed summary of extended header information such as file creations or deletions ("new" or "gone", optionally "+l" if it’s a symlink) and mode changes ("+x" or "-x" for adding or removing executable bit respectively) in diffstat. The information is put between the filename part and the graph part. Implies --stat.

I like the below command to compare a specific commit and its last commit:

git diff <commit-hash>^-

Example:

git diff cd1b3f485^-

You could use git diff HEAD HEAD^1 to see the diff with the parent commit.

If you only want to see the list of files, add the --stat option.

git difftool COMMIT^ <commit hash>

is also possible if you have configured your difftool.

See here how to configure difftool. Or the manual page here.

Additionally, you can use git diff-tree --no-commit-id --name-only -r <commit hash> to see which files been changed/committed in a give commit hash.

To see author and time by commit, use git show COMMIT. Which will result in something like this:

commit 13414df70354678b1b9304ebe4b6d204810f867e
Merge: a2a2894 3a1ba8f
Author: You <you@you.com>
Date:   Fri Jul 24 17:46:42 2015 -0700

     Merge remote-tracking branch 'origin/your-feature'

If you want to see which files had been changed, run the following with the values from the Merge line above, git diff --stat a2a2894 3a1ba8f.

If you want to see the actual diff, run git --stat a2a2894 3a1ba8f.

For checking complete changes:

  git diff <commit_Id_1> <commit_Id_2>

For checking only the changed/added/deleted files:

  git diff <commit_Id_1> <commit_Id_2> --name-only

NOTE: For checking diff without commit in between, you don't need to put the commit ids.

If you just want to see the changes in the latest commit, simply git show will give you that.

The following code will show the current commit

git show HEAD

This command will get you the Git parent commit-hash:

git log -n 2 <commit-hash>

After that git diff-tool <commit-hash> <parent-commit-hash>

Example:

bonnie@bonnie ~/ $ git log -n 2 7f65b9a9d3820525766fcba285b3c678e889fe3

commit 7f65b9a9d3820525766fcba285b3c678e889fe3b
Author: souparno <souparno.majumder@gmail.com>
Date:   Mon Jul 25 13:17:07 2016 +0530

CSS changed to maintain the aspect ratio of the channel logos and to fit them properly.

commit c3a61f17e14e2b80cf64b172a45f1b4826ee291f
Author: souparno <souparno.majumder@gmail.com>
Date:   Mon Jul 25 11:28:09 2016 +0530

The ratio of the height to width of the channel images are maintained.

After this

git difftool 7f65b9a9d3820525766fcba285b3c678e889fe3b c3a61f17e14e2b80cf64b172a45f1b4826ee291f

I'm running Git version 2.6.1.windows.1 on Windows 10, so I needed a slight modification to Nevik's answer (tilde instead of caret):

git diff COMMIT~ COMMIT

Another option is to quote the caret:

git diff "COMMIT^" COMMIT

It is also possible to review changes between two commits for a specific file.

git diff <commit_Id_1> <commit_Id_2> some_dir/file.txt

A few answers miss a special case. How to view changes made by the Root Commit as it does not have a parent/ancestor.

Both

git diff <root_commit>^..<root_commit>

and

git diff <root_commit>~..<root_commit>

throw an error.

$git diff 27e521ca73a46b2d3a28568dc49fced81e46aaea~ 27e521ca73a46b2d3a28568dc49fced81e46aaea
fatal: ambiguous argument '27e521ca73a46b2d3a28568dc49fced81e46aaea~': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

git diff <root_commit>^!

shows diff btw root commit and HEAD. Like so:

$ git diff 27e521ca73a46b2d3a28568dc49fced81e46aaea^!
diff --git a/file1.txt b/file1.txt
new file mode 100644
index 0000000..80f3f1a
--- /dev/null
+++ b/file1.txt
@@ -0,0 +1,5 @@
+Create the first file.
+
+Add some placeholder text to first file.
+
+
diff --git a/file2.txt b/file2.txt
new file mode 100644
index 0000000..66e494f
--- /dev/null
+++ b/file2.txt
@@ -0,0 +1,6 @@
+This is the second file.
+
+It has an uncommited commit.
+
+We use it to demo default `git diff` behaviour.
+

(These are changes made by all commits btw my root commit and HEAD).

For Root Commit

I find only

git show --color --pretty=format:%b <root_commit_hash>

works.

Like so:

$ git show --color --pretty=format:%b 27e521ca73a46b2d3a28568dc49fced81e46aaea

diff --git a/README b/README
new file mode 100644
index 0000000..12a04f0
--- /dev/null
+++ b/README
@@ -0,0 +1,6 @@
+# git-diff-demo
+
+This repo documents the demo of the git diff command.
+We will have options, and use cases.

(My root commit added only the README)

In case of checking the source change in a graphical view, use:

gitk (your commit id goes here)

For example:

gitk HEAD~1 

git difftool "HASH_in_history" -- "path_to_file"