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I have a script that works fine in one branch and is broken in another. I want to look at the two versions side-by-side and see what's different. Is there a way to do this?

To be clear I'm not looking for a compare tool (I use Beyond Compare). I'm looking for a Git diff command that will allow me to compare the master version to my current branch version to see what has changed. I'm not in the middle of a merge or anything. I just want to say something like

git diff mybranch/myfile.cs master/myfile.cs
Peter Mortensen
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Micah
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14 Answers14

2906

git diff can show you the difference between two commits:

git diff mybranch master -- myfile.cs

Or, equivalently:

git diff mybranch..master -- myfile.cs

Note you must specify the relative path to the file. So if the file were in the src directory, you'd say src/myfile.cs instead of myfile.cs.

Using the latter syntax, if either side is HEAD it may be omitted (e.g., master.. compares master to HEAD).

You may also be interested in mybranch...master (from git diff documentation):

This form is to view the changes on the branch containing and up to the second <commit>, starting at a common ancestor of both <commit>. git diff A...B is equivalent to git diff $(git-merge-base A B) B.

In other words, this will give a diff of changes in master since it diverged from mybranch (but without new changes since then in mybranch).

In all cases, the -- separator before the file name indicates the end of command line flags (mind the space between the separator and the filename). This is optional unless Git will get confused if the argument refers to a commit or a file, but including it is not a bad habit to get into. See Dietrich Epp's answer to Meaning of Git checkout double dashes for a few examples.

The same arguments can be passed to git difftool if you have one configured.

Tms91
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dahlbyk
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  • is it possible that if there's no changes it wont launch the difftool? – Micah Nov 04 '10 at 18:37
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    And if neither of the two versions you want to compare is the work tree, you can use `git diff branch1 branch2 myfile.cs`. (The `--` shouldn't be necessary anymore, as it can only take up to two revision arguments.) – Cascabel Nov 04 '10 at 18:43
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    I've tried every version of this and nothing happens. I have my difftool configured (it works for merging). I have a file called bd.ps1. Every version of the command I type does nothing. Doesn't even give an errer. WTH!?!?! – Micah Nov 04 '10 at 18:46
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    @Micah: Are you trying it with plain diff too? Are you correctly typing the path relative to the current directory? (It will silently show no diff if the file doesn't exist, and you use the `--`. Common and easy mistake to make.) – Cascabel Nov 04 '10 at 18:58
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    the file is in the root directory of my branch (and that's directory I'm running the command from) git diff alerts master -- bd.ps1 (just fails silently) – Micah Nov 04 '10 at 19:25
  • @Micah: Hm. Fails, or succeeds? Check the exit code. If it's reporting success, it means it thinks there's no difference; I'm guessing that's the case. Is one of those branches not where you think it is? This doesn't happen to be a public repository, does it - I'd be happy to just look, if it is. – Cascabel Nov 05 '10 at 01:10
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    This didn't work for me unless I included the full path to the file, as shown by `git diff --name-status branch1..branch2` (probably obvious, but thought I'd mention it in case someone else has the same trouble I did). – hBrent Aug 19 '13 at 21:42
  • This also did not work for me. I used $ git diff {branch} master --{filename copied from git status result} and it just said "usage: git diff [] [ []] [--] [...]" – CF_HoneyBadger Sep 08 '14 at 19:26
  • Did you have a space between `--` and `{filename}`? If not, Git will think you were trying to specify a `--long-switch`. – dahlbyk Sep 12 '14 at 15:56
  • dahlbyk solution works for me, however for curiosity sake I attempted @Jefromi version using -- but it only gave this error: fatal: ambiguous argument 'myflie.cs': unknown revision or path not in the working tree. Use '--' to separate paths from revisions, like this: 'git [...] -- [...]' – jasonleonhard Nov 19 '14 at 20:47
  • Can you be more specific about the command you used? If you provided two refs and a path, the only thing I can think of is an incorrect path. – dahlbyk Nov 24 '14 at 06:40
  • doubledash -- is necessary for me, at least when using the glob `"*/filename.txt"` – neaumusic Mar 02 '15 at 22:39
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    The order of mybranch and master is also important. The file in the first branch will be shown with '-' prefixes, the file in the second branch will be shown with '+' prefixes. – timbo Sep 14 '15 at 23:48
  • @Jefromi Correct me if I am wrong, so if you want to compare from your **current** work tree with a branch you would just do: `git diff anotherBranch myfile.cs` ? – mfaani Aug 16 '16 at 17:35
  • Correct me if I'm wrong. This only fits the need of 'comparing two commits', it doesn't address the situation where you want to compare your **uncommited** work with a commited file from another branch? But the answer [here](http://stackoverflow.com/questions/9113280/diff-current-working-copy-of-a-file-with-another-branchs-committed-copy/9113407#9113407) does address it right? – mfaani Aug 31 '16 at 21:03
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    Omitting a second `` value will "view the changes you have in your working tree relative to the named . You can use HEAD to compare it with the latest commit, or a branch name to compare with the tip of a different branch." So `git diff mybranch -- myfile.cs` will compare the working directory's `myfile.cs` with that file in `mybranch`. – dahlbyk Aug 31 '16 at 21:14
  • When you do this which one shows up as adding and which one shows up subtracing? – David Sopko Feb 08 '17 at 21:22
  • Can I compare the file between local branches, not from remote branches?@dahlbyk – soarinblue Aug 10 '17 at 03:17
  • @soarinblue Yes, in my example above both `mybranch` and `master` are local branches. – dahlbyk Aug 14 '17 at 06:53
  • The key was "Are you correctly typing the path relative to the current directory?" Thanks to @Jefromi :) Now it works. – Miklos Krivan Nov 23 '17 at 10:27
  • From Win cmd prompt - after checking out branch to diff with `master` branch: Had some issues but found to resolve easily as `c:\>git diff c:\..master /`. This was more convenient as I had multiple files and i could just use up arrow key to bring back previous command and just paste the relative path of next file from the output of `git diff --name-status`. Its better than the other option providing full path of the file as it would be difficult to edit the file path each time from relative to full. – Ulysses Jul 09 '18 at 06:34
  • it should also be explained how to read the git diff – Charlie Parker Sep 21 '22 at 23:13
  • Neither of these work. – Cerin Nov 23 '22 at 19:52
  • @Cerin this behavior hasn't changed in at least 12 years. Are you trying to diff a renamed file or something? – dahlbyk Nov 29 '22 at 15:40
  • Is there a way to see changes made on my branch, but ignore those lines which are already on master? Please help me to achieve this result: https://stackoverflow.com/q/76791390/4632019 – Eugen Konkov Jul 28 '23 at 22:48
581

You can do this: git diff branch1:path/to/file branch2:path/to/file

If you have difftool configured, then you can also: git difftool branch1:path/to/file branch2:path/to/file

Related question: How do I view 'git diff' output with my preferred diff tool/ viewer?

Peter Mortensen
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Tim Henigan
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    Using the colons is not really a great way - it means you're referencing the files through the tree objects, so you have to type out the full path, instead of relative to your current directory. – Cascabel Nov 04 '10 at 18:42
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    @Jefromi, this may have changed in a more recent version, but at least now you can use relative paths (e.g. `branch1:./file`). This is also useful if the file is in a separate location between branches (e.g. `git diff branch1:old/path/to/file branch2:new/path/to/file`). – redbmk Mar 15 '14 at 00:36
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    @redbmk Yeah, that was sometime between 2010 and now! Still, if it's the same file on both branches, no need to do it like this, just `git diff branch1 branch2 path/to/file`. – Cascabel Mar 15 '14 at 00:47
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    @jefromi cool, I wasn't sure the timeline on when that was added. Yeah I would normally use the syntax you mentioned, but Tim's answer helped me figure out how to compare files with different paths, even though it's not really what the question was asking – redbmk Mar 17 '14 at 15:47
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    While I love this idea, I can't get this syntax to work or find any mention of it in the git diff docs. What am I missing? Thanks! – yoyo Dec 17 '14 at 23:22
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    On Windows still use `/` path separator else `git diff` silently does nothing. – Vasiliy Zverev Jul 02 '19 at 10:25
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    this answer is the best for the case that a file was renamed, especially if the old name is reused in the new branch. putting this here for people `ctrl+f`ing for "renamed" or "different files" or "different file names" – Joey Baruch Sep 15 '20 at 14:48
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    One of the ways file can change is surely a change of its name! That's why this is a better answer than the accepted one. – T.V. Feb 16 '21 at 04:55
  • Instead of using 'mybranch', I found I could also do the commit id which is kind of helpful in my environment. – Harlin Jan 11 '23 at 20:20
217

More modern syntax:

git diff ..master path/to/file

The double-dot prefix means "from the current working directory to". You can also say:

  • master.., i.e. the reverse of above. This is the same as master.
  • mybranch..master, explicitly referencing a state other than the current working tree.
  • v2.0.1..master, i.e., referencing a tag.
  • [refspec]..[refspec], basically anything identifiable as a code state to Git.
Peter Mortensen
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Joe Atzberger
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44

There are many ways to compare files from two different branches:

  • Option 1: If you want to compare the file from n specific branch to another specific branch:

    git diff branch1name branch2name path/to/file

    Example:

    git diff mybranch/myfile.cs mysecondbranch/myfile.cs

    In this example you are comparing the file in “mybranch” branch to the file in the “mysecondbranch” branch.

  • Option 2: Simple way:

     git diff branch1:file branch2:file

    Example:

     git diff mybranch:myfile.cs mysecondbranch:myfile.cs

    This example is similar to the option 1.

  • Option 3: If you want to compare your current working directory to some branch:

    git diff ..someBranch path/to/file

    Example:

    git diff ..master myfile.cs

    In this example you are comparing the file from your actual branch to the file in the master branch.

Peter Mortensen
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Javier C.
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23

For Visual Studio Code I strongly suggest the extension:

Git History Diff docs

You can use it two compare between files or even branches!

From console, you can simply use this command :

git diff <Your_Branch> <Branch_To_Compare_With> -- myfile.cs
Mouad Chaouki
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20

If you want to make a diff against the current branch you can commit it and use:

git diff $BRANCH -- path/to/file

This way it will diff from the current branch to the referenced branch ($BRANCH).

Peter Mortensen
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Paulo Fidalgo
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17

I simply do git diff branch1 branch2 path/to/file

This checks for differences between the files. Changes in branch1 would be in red. Changes in branch2 would be in green.

It's assumed that branch1 is the past and branch2 is the future. You can reverse this by reversing the order of the branches in the diff: git diff branch2 branch1

Igbanam
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10

There are two scenarios to compare files:

Scenario 1: Compare files at remote branches (both branches should exists in the remote repository)

Scenario 2: Compare local files (at the local working area copy) to the files at the remote repository.

The logic is simple. If you provide two branch names to diff, it will always compare the remote branches, and if you provide only one branch name, it will always compare your local working copy with the remote repository (the one you provided). You can use range to provide remote repositories.

E.g., check out a branch:

git checkout branch1

git diff branch2 [filename]

In this case, if you provide filename, it will compare your local copy of filename with the remote branch named "branch2".

git diff branch1 branch2 [filename]

In this case, it will compare filename from remote branches named "branch1" vs "branch2"

git diff ..branch2 [filename]

In this case also, it will compare filename from remote branches named "branch1" vs "branch2". So, it's the same as above. However, if you have just created a branch from another branch, say "master" and your current branch doesn't exists on the remote repository, it will compare remote "master" vs. remote "branch2".

Peter Mortensen
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Dharmender Rawat
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5

I am agreeing with the answer by dahlbyk. If you want the diff to be written to a diff file for code reviews, use the following command.

git diff branch master -- filepath/filename.extension > filename.diff --cached
Peter Mortensen
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Azad
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5

In my case, I use the below command:

git diff <branch name> -- <file path + file name>

This command can help you compare the same file in two different branches.

SKT
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4

Use commit hashes as this:

git diff <hash1> <hash2> <filename>

where hash1 can be any commit from any branch, and the same for hash2.

Peter Mortensen
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prometeu
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3

There is another interesting point about these various ways of doing the comparison: I want to compare a file in my current branch to the same file in another branch. If I use

git difftool otherbranch.. filespec

I end up comparing two files which are actually in my temporary folder. However, If I use

git difftool otherbranch filespec

I end up comparing a file in my temporary folder (the version on otherbranch) with the actual file in my Git folder, which a) makes it much easier to tell which is which, and b) means I can use the diff tool (Beyond Compare 4 in my case) to copy changes from my other branch into my current branch.

Peter Mortensen
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Dave
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1

In order to compare two files in Git Bash you need to use the command:

git diff <Branch name>..master -- Filename.extension

This command will show the difference between the two files in Bash itself.

Peter Mortensen
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Rishav_SO
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1

The best way to do it is by using git diff in the following way:

git diff <source_branch> <target_branch> -- file_path

It will check the difference between files in those branches. Take a look at this article for more information about Git commands and how they work.

Peter Mortensen
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Nesha Zoric
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