git remove merge commit from history

Starting with the repo in the original state

To remove the merge commit and squash the branch into a single commit in the mainline

Use these commands (replacing 5 and 1 with the SHAs of the corresponding commits):

git checkout 5 git reset --soft 1 git commit --amend -m '1 2 3 4 5' git rebase HEAD master 

To retain a merge commit but squash the branch commits into one:

Use these commands (replacing 5, 1 and C with the SHAs of the corresponding commits):

git checkout -b tempbranch 5 git reset --soft 1 git commit --amend -m '1 2 3 4 5' git checkout C git merge --no-ff tempbranch git rebase HEAD master 

To remove the merge commit and replace it with individual commits from the branch

Just do (replacing 5 with the SHA of the corresponding commit):

git rebase 5 master 

And finally, to remove the branch entirely

Use this command (replacing C and D with the SHAs of the corresponding commits):

git rebase --onto C D~ master 

To Just Remove a Merge Commit

If all you want to do is to remove a merge commit (2) so that it is like it never happened, the command is simply as follows

git rebase --onto <sha of 1> <sha of 2> <blue branch>

And now the purple branch isn't in the commit log of blue at all and you have two separate branches again. You can then squash the purple independently and do whatever other manipulations you want without the merge commit in the way.

There are two ways to tackle this based on what you want:

Solution 1: Remove purple commits, preserving history (incase you want to roll back)

git revert -m 1 <SHA of merge> 

-m 1 specifies which parent line to choose

Purple commits will still be there in history but since you have reverted, you will not see code from those commits.

Solution 2: Completely remove purple commits (disruptive change if repo is shared)

git rebase -i <SHA before branching out> 

and delete (remove lines) corresponding to purple commits.

This would be less tricky if commits were not made after merge. Additional commits increase the chance of conflicts during revert/rebase.

For full control over the operation and to preserve any merge commits you want to keep along the way, the modern approach is to use

git rebase -i -r

From man git rebase of git version 2.44.2 about -r:

-r, --rebase-merges[=(rebase-cousins|no-rebase-cousins)], --no-rebase-merges By default, a rebase will simply drop merge commits from the todo list, and put the rebased commits into a single, linear branch. With --rebase-merges, the rebase will instead try to preserve the branching structure within the commits that are to be rebased, by recreating the merge commits. Any resolved merge conflicts or manual amendments in these merge commits will have to be resolved/re-applied manually. --no-rebase-merges can be used to countermand both the rebase.rebaseMerges config option and a previous --rebase-merges. When rebasing merges, there are two modes: rebase-cousins and no-rebase-cousins. If the mode is not specified, it defaults to no-rebase-cousins. In no-rebase-cousins mode, commits which do not have <upstream> as direct ancestor will keep their original branch point, i.e. commits that would be excluded by git-log(1)'s --ancestry-path option will keep their original ancestry by default. In rebase-cousins mode, such commits are instead rebased onto <upstream> (or <onto>, if specified). It is currently only possible to recreate the merge commits using the ort merge strategy; different merge strategies can be used only via explicit exec git merge -s <strategy> [...] commands. See also REBASING MERGES and INCOMPATIBLE OPTIONS below. 

I wanted a simpler way of achieving Warren's rebase onto approach as I had a hard time making sense of the appropriate hashes and their meaning and I did not want to get into a detached head state (but point the result directly to the local! branch).

My use case often is to purge an unwanted merge from a current feature branch from history. So I want to be able to purge a merge commit by its id from the currently checked out branch with no further hashes as an input.

I wrote two helper scripts enabling me this workflow:

1. Make sure you are in the right branch you wish to purge a merge from.

    $> git checkout branch-containing-unwanted-merge 

2. Find the appropriate merge commit hash:

   $> ./list-merges.sh 3 c952c106b94e0353a6e8db93cb2fd6495404a07b 2025-10-08 my-unwanted-merge 305de5b3f0fdd02ba8d74520e957fd7db5336576 2025-10-06 some-other-merge 7b18a1eadda78d64b157a2dbd4696cf6be1bfec4 2025-10-02 yet-another-merge 

   The hash of the unwanted merge, in my case, is c952c106b94e0353a6e8db93cb2fd6495404a07b.

3. Run the purge. The hash becomes the input of my purge command:

   $> ./purge-merge.sh c952c106b94e0353a6e8db93cb2fd6495404a07b Starting to purge merge from history (local only, no force pushing) Target Branch: branch-containing-unwanted-merge Merge to Undo: c952c106b94e0353a6e8db93cb2fd6495404a07b New Base (First Parent): f1e12273200300694d6fe63a9d57fa5c505d4927 History rewritten. The merge commit is gone. Local branch is now at the new tip. WARNING: To update the remote branch, run: git push --force-with-lease origin branch-containing-unwanted-merge 

4. You may now force-push the local branch to the remote as recommended.

These are the scripts:

list-merges.sh

#!/usr/bin/env bash N=${1:-5} if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then echo "Error: Not inside a Git repository." exit 1 fi git log --merges -n "$N" \ --pretty=format:$'%C(yellow)%H%C(reset)\t%C(cyan)%ad%C(reset)\t%s' \ --date=short --color=always \ | sed "s/\tMerge branch '\([^']*\)' into .*$/\t\1/" echo exit 0 

 $>\cat purge-merge.sh #!/usr/bin/env bash MERGE_SHA=$1 if [ -z "${MERGE_SHA}" ]; then echo "Error: Please provide the merge commit SHA." exit 1 fi if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then echo "Error: Not inside a Git repository." exit 1 fi if ! git diff-index --quiet HEAD --; then echo "Error: Working directory is not clean." echo "Please commit, stash, or reset your changes before running this command." exit 1 fi BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD) FIRST_PARENT=$(git rev-parse "${MERGE_SHA}^1") cat <<EOF Starting to purge merge from history (local only, no force pushing) Target Branch: ${BRANCH_NAME} Merge to Undo: ${MERGE_SHA} New Base (First Parent): ${FIRST_PARENT} EOF if git rebase --onto "${FIRST_PARENT}" "${MERGE_SHA}" HEAD; then git branch -f "${BRANCH_NAME}" HEAD git checkout "${BRANCH_NAME}" cat <<EOF_SUCCESS Merge Undo Successful History rewritten. The merge commit is gone. Local branch is now at the new tip. WARNING: To update the remote branch, run: git push --force-with-lease origin ${BRANCH_NAME} EOF_SUCCESS exit 0 else cat <<'EOF_FAILURE' Rebase Failed --- The rebase stopped due to conflicts or an error. Resolve conflicts, then run: git rebase --continue If you want to abort, run: git rebase --abort EOF_FAILURE exit 1 fi