2216
votes

I want to merge two branches that have been separated for a while and wanted to know which files have been modified.

Came across this link: http://linux.yyz.us/git-howto.html which was quite useful.

The tools to compare branches I've come across are:

  • git diff master..branch
  • git log master..branch
  • git shortlog master..branch

Was wondering if there's something like "git status master..branch" to only see those files that are different between the two branches.

Without creating a new tool, I think this is the closest you can get to do that now (which of course will show repeats if a file was modified more than once):

  • git diff master..branch | grep "^diff"

Was wondering if there's something I missed...

18
How many others find the title of this question misleading? It is actually about finding the file differences between two branches. What I came here looking for was how to see file differences between two revisions on the same branch. Or am I the only one?Sandeepan Nath
@SandeepanNath: with git there is no difference. You are ALWAYS referring to individual commits.Samuel O'Malley
@SamuelO'Malley I am new to git and considering the seemingly common branching strategy wherein all the branches are finally merged to the master branch and ultimately the master is rolled out. Now, considering the event of a rollout, where the production is already at master, but behind the tip (by one revision if the last rollout happened after the last master merge), I would like to see the differences between these two revisions, to find out what would be rolled out. I would not like to look at the branch which was last merged. Correct me if I am wrong.Sandeepan Nath
@SandeepanNath: instead of using the branch names then you can take the answers below and just specify the commit IDs instead. Or even refer the commits by their tag names if you create tags when rolling out.Samuel O'Malley
@SandeepanNath You cannot compare 2 branches, you must specify the revision. So comparing 2 branches is comparing 2 revisions.Bastien Vandamme

18 Answers

2724
votes

To compare the current branch against master branch:

$ git diff --name-status master

To compare any two branches:

$ git diff --name-status firstbranch..yourBranchName

There is more options to git diff in the official documentation (and specifically --name-status option).

424
votes

Try

$ git diff --stat --color master..branchName

This will give you more info about each change, while still using the same number of lines.

You can also flip the branches to get an even clearer picture of the difference if you were to merge the other way:

$ git diff --stat --color branchName..master
169
votes

Also keep in mind that git has cheap and easy branching. If I think a merge could be problematic I create a branch for the merge. So if master has the changes I want to merge in and ba is my branch that needs the code from master I might do the following:

git checkout ba
git checkout -b ba-merge
git merge master
.... review new code and fix conflicts....
git commit
git checkout ba
git merge ba-merge
git branch -d ba-merge
git merge master

End result is that I got to try out the merge on a throw-away branch before screwing with my branch. If I get my self tangled up I can just delete the ba-merge branch and start over.

58
votes

If anyone is trying to generate a diff file from two branches :

git diff master..otherbranch > myDiffFile.diff
45
votes

There is also a GUI based method.

You can use gitk.

  1. Run:

    $ gitk --all
    
  2. Right click on a commit of a branch and select Mark this commit in the pop-up menu.

  3. Right click on a commit of another branch and select Diff this -> marked commit or Diff marked commit -> this.

Then there will be a changed files list in the right bottom panel and diff details in the left bottom panel.

38
votes

One more option, using meld in this case:

git difftool -d master otherbranch

This allows not only to see the differences between files, but also provides a easy way to point and click into a specific file.

28
votes

Note that git makes it easy to just try out the merge and back away from any problems if you don't like the result. It might be easier than looking for potential problems in advance.

18
votes

And if you are looking for changes only among certain file(s), then:

git diff branch1 branch2 -- myfile1.js myfile2.js

branch1 is optional and your current branch (the branch you are on) will be considered by default if branch1 is not provided. e.g:

git diff master -- controller/index.js
15
votes

When working collaboratively, or on multiple features at once, it's common that the upstream or even your master contains work that is not included in your branch, and will incorrectly appear in basic diffs.

If your Upstream may have moved, you should do this:

git fetch
git diff origin/master...

Just using git diff master can include, or fail to include, relevant changes.

11
votes

If you are using IntelliJ IDEA, you can also compare any branch with your current working branch. See http://www.jetbrains.com/idea/webhelp/merging-deleting-and-comparing-branches.html#d288093e3827 for more info. This is available in the free edition as well.

8
votes

There are two branches lets say

  • A (Branch on which you are working)
  • B (Another branch with which you want to compare)

Being in branch A you can type

git diff --color B

then this will give you a output of

enter image description here

The important point about this is

  1. Text in green is inside present in Branch A

  2. Text in red is present in Branch B

8
votes

There are plenty of answers here, but I wanted to add something that I commonly use. IF you are in one of the branches that you would like to compare I typically do one of the following. For the sake of this answer we will say that we are in our secondary branch. Depending on what view you need at the time will depend on which you choose, but most of the time I'm using the second option of the two. The first option may be handy if you are trying to revert back to an original copy -- either way, both get the job done!

This will compare master to the branch that we are in (which is secondary) and the original code will be the added lines and the new code will be considered the removed lines

git diff ..master

OR

This will also compare master to the branch that we are in (which is secondary) and the original code will be the old lines and the new code will be the new lines

git diff master..
1
votes

For people who are looking for a GUI solution, Git Cola has a very nice "Branch Diff Viewer (Diff -> Branches..).

1
votes

If you are using Github / Github Enterprise, you can use the Web UI by hitting the url /compare of your repository path, for instance, https://github.com/http4s/http4s/compare. You can select the branch / commit / tag that you want to compare: Github Compare Screenshot

And the diff will be presented in the github interface at the url /compare/{x1}...{x2} where are x2 and x1 are the branch / commit / tag you want to compare, for instance: https://github.com/http4s/http4s/compare/main...dotty

You can see more in the Github Doc.

0
votes
git diff revision_n revision_m

if revision_n and revision_m are successive commits then it outputs same as git show revision_m

-1
votes

You can also use a visual diff.

For example, if you are using Sourcetree, you can simply select any two commits in log view.

(I personally prefer using a GUI in most cases for this, and I'm posting this for those who may not be familiar with GUI options.)

-2
votes

If you like GUI and are using Windows, here is an easy way.

  1. Download WinMerge
  2. Check out the two branches into different folders
  3. Do a folder by folder compare using WinMerge. You can also easily make modifications if one of the branches is the one you are working on.
-3
votes

You can also easily compare branches for changed files using for example TortoiseGit. Just click on Browse References and pick the branches you want to compare.

For example if you compare your branch with master you will get as a result list of files that will be changed in master if you decide to merge your-branch into master.

Remmber that you will have different result if you compare master with your-branch and your-branch with master.