Git: How to squash all commits on branch

Checkout the branch for which you would like to squash all the commits into one commit. Let's say it's called feature_branch.

git checkout feature_branch

Step 1:

Do a soft reset of your origin/feature_branch with your local main branch (depending on your needs, you can reset with origin/main as well). This will reset all the extra commits in your feature_branch, but without changing any of your file changes locally.

git reset --soft main

Step 2:

Add all of the changes in your git repo directory, to the new commit that is going to be created. And commit the same with a message.

# Add files for the commit.
git add ...
git commit -m "commit message goes here"

What you're doing is pretty error-prone. Just do:

git rebase -i master

which will automatically rebase only your branch's commits onto the current latest master.

Another way to squash all your commits is to reset the index to master:

git checkout yourBranch
git reset $(git merge-base master $(git branch --show-current))
git add -A
git commit -m "one commit on yourBranch"

This isn't perfect as it implies you know from which branch "yourBranch" is coming from.
Note: finding that origin branch isn't easy/possible with Git (the visual way is often the easiest, as seen here).

Note: git branch --show-current has been introduced with Git 2.22 (Q2 2019).

---

EDIT: you will need to use git push --force

---

Karlotcha Hoa adds in the comments:

For the reset, you can do

git reset $(git merge-base master $(git rev-parse --abbrev-ref HEAD)) 

[That] automatically uses the branch you are currently on.
And if you use that, you can also use an alias, as the command doesn't rely on the branch name.

---

sschoof adds in the comments:

Since my default branch is called main and my search had multi times brought me here:
To copy it for my next time

git reset $(git merge-base main $(git rev-parse --abbrev-ref HEAD))