What is the difference between git am and git apply?

Question

Both git am and git apply can be used to apply patches. I fail to see the difference. I see a difference now: git am automatically commits whereas git apply only touches the files but doesn't create a commit. Is that the only difference?

`am` could be thought of as an abbreviation of `Apply Mail`... — Philip Oakley, Sep 04 '12 at 10:05

score 226 · Accepted Answer · edited Jun 26 '18 at 14:14

226

Both the input and output are different:

git apply takes a patch (e.g. the output of git diff) and applies it to the working directory (or index, if --index or --cached is used).
git am takes a mailbox of commits formatted as an email messages (e.g. the output of git format-patch) and applies them to the current branch.

git am uses git apply behind the scenes, but does more work before (reading a Maildir or mbox, and parsing email messages) and after (creating commits).

edited Jun 26 '18 at 14:14

Maximo Mussini

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answered Sep 02 '12 at 22:23

georgebrock

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Note: `git apply` seems to also accept `git format-patch` output. – Ciro Santilli OurBigBook.com Jun 24 '15 at 08:31
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`git apply` would work for output from `git format-patch` as well but the changes would be unstaged and would need to be committed (thus creating a different commit point in the index they are applied to). With `git am` you would be carrying the commit information (along with author, etc.) into the index it is applied to. `git apply` then is for patching your repo (bad), `git am` can take legit feature changes and include it into your repo (preferred approach). – Prasoon Joshi May 19 '17 at 13:44
Which of these would I normally want if I used `GITK` to view my tree and then made a patch from the context menu on my uncommitted changes? I can't imagine git am would work very well if there's no commit information for it to create the commits, so I would guess git apply is what I want.…
…I guess, both in the name of general prudence and because of the moderation strike (My trust for this site is running a little low right now, if they don't understand the problem with AI answers), I should http://www.tryitands.ee – Twisted on STRIKE at1687989253 Jun 28 '23 at 16:03
looks like git apply is the command to do, in the situation I described above. I would assume the same applies if I create the patch from a sequence of commands in GITK? but I don't need to know right now, so I'm not going to try it and see. Feel free to do so yourself! – Twisted on STRIKE at1687989253 Jun 28 '23 at 20:35

score 28 · Answer 2 · answered Sep 02 '12 at 22:21

git apply is for applying straight diffs (e.g. from git diff) whereas git am is for applying patches and sequences of patches from emails, either mbox or Maildir format and is the "opposite" of git format-patch. git am tries to extract commit messages and author details from email messages which is why it can make commits.

0x90 · Answer 3 · 2021-03-16T12:30:15.580

With git am you apply the patch so when you run git status you won't see any local changes, but git log will show the patch have been committed to the source code.

But with git apply you make the changes in the source files as if you were writing the code yourself, consequently git status and git diff will output the changes appeared in the patch you applied. Hence with git apply you can fix/add more changes and git add them together as a single new patch.

What is the difference between git am and git apply?

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