Git stash uncached: how to put away all unstaged changes?

The accepted answer also stashes staged changes as a few have pointed out. Here's a way to do it without getting your staged changes in the stash.

The idea is to do a temporary commit of your staged changes, then stash the unstaged changes, then un-commit the temp commit:

# temp commit of your staged changes:
$ git commit --message "WIP"

# -u option so you also stash untracked files
$ git stash -u

# now un-commit your WIP commit:
$ git reset --soft HEAD^

At this point, you'll have a stash of your unstaged changes and will only have your staged changes present in your working copy.

Update 2:
I'm not sure why people are complaining about this answer, it seems to be working perfectly with me, for the untracted files you can add the -u flag

The full command becomes git stash --keep-index -u

And here's a snippet from the git-stash help

If the --keep-index option is used, all changes already added to the index are left intact.

If the --include-untracked option is used, all untracked files are also stashed and then cleaned up with git clean, leaving the working directory in a very clean state. If the --all option is used instead then the ignored files are stashed and cleaned in addition to the untracked files.

And this is a gif of how it looks:

Update:

Even though this is the selected answer, a lot have pointed out that the [answer below](https://stackoverflow.com/a/34681302/292408) is the correct one, I recommend checking it out.

I tested my answer again today (31/1/2020) against git version 2.24.0, and I still believe that it's correct, I added a small note above about the untracked files. If you think it's not working please also mention your git version.

Old answer:
If the --keep-index option is used, all changes already added to the index are left intact:

git stash --keep-index

From the documentation of git-stash:

Testing partial commits

You can use git stash save --keep-index when you want to make two or more commits out of the changes in the work tree, and you want to test each change before committing:

# ... hack hack hack ...
$ git add --patch foo            # add just first part to the index
$ git stash save --keep-index    # save all other changes to the stash
$ edit/build/test first part
$ git commit -m 'First part'     # commit fully tested change
$ git stash pop                  # prepare to work on all other changes
# ... repeat above five steps until one commit remains ...
$ edit/build/test remaining parts
$ git commit foo -m 'Remaining parts'

But, if you just want to visually check the staged changes only, you can try difftool:

git difftool --cached