We've all been there, you just finished correcting all the typos of your README or documentation, you have already made the commit, push the changes, and then you realise you misspelled a word. "Damn" you think "do I have to make a new commit for this small change?", "that will only make the history of the repo bigger and messier". Good thing there is a way of fixing this.

Welcome to squashing commits. I am going to explain the way I do it, I don't know if it's the best but it works perfectly for me, so it should work for you.

Say you have your history this way:

$ git log --abbrev-commit --pretty=oneline
9f0fd1c (HEAD -> master) anther typo i had not seen
5bc004b typo I missed
78cf95f fixing typos in README
773350e good commit

The 78cf95f is the good one (the one we want to keep), 5bc004b and 9f0fd1c are the ones we want to get rid off. Meaning it would be nice that the last two commits could be "merged" with 78cf95f this way we would only have one clean and simple commit for correcting typos.

What do we do? We can use the rebase subcommand to squash the other two commits under that one:

$ git rebase -i 78cf95f^ # please note the ^

After we run this a text editor will be open and this will be displayed:

pick 78cf95f fixing typos in README
pick 5bc004b typo I missed
pick 9f0fd1c anther typo i had not seen

# some comments

Then we can just squash the commits we want, so:

pick 78cf95f fixing typos in README
squash 5bc004b typo I missed # edit this line
squash 9f0fd1c anther typo i had not seen # edit this line

# some comments

We just need to rewrite pick -> squash. Then we are good to go, save and quit your text editor.

The text editor will be opened again. This time we can modify the commit messages, in case we want to add something, or just remove the message for the two commits we are squashing. Once you are happy with the result, just save, quit, and voila.

$ git log --abbrev-commit --pretty=oneline
0335a16 (HEAD -> master) fixing typos in README
773350e good commit

You now have a single, clean, commit. No need to contaminate your history with unnecessary commits.