> [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/13950) in GitLab 11.5.
GitLab provides a way of leaving comments in any part of the file being changed
in a Merge Request. To do so, click the **...** button in the gutter of the Merge Request diff UI to expand the diff lines and leave a comment, just as you would for a changed line.
in a Merge Request. To do so, click the **{comment}****comment** icon in the gutter of the Merge Request diff UI to expand the diff lines and leave a comment, just as you would for a changed line.
![Comment on any diff file line](img/comment-on-any-diff-line.png)
### Commenting on multiple lines
> - [Introduced](https://gitlab.com/gitlab-org/ux-research/-/issues/870) in GitLab 13.2.
> - It's deployed behind a feature flag, enabled by default.
> - It's enabled on GitLab.com.
> - It's able to be enabled or disabled per-project
> - It's recommended for production use.
> - For GitLab self-managed instances, GitLab administrators can opt to [enable it](#enable-or-disable-multiline-comments-core-only). **(CORE ONLY)**
GitLab provides a way to select which lines of code a comment refers to. After starting a comment
a dropdown selector is shown to select the first line that this comment refers to.
The last line is the line that the comment icon was initially clicked on.
New comments default to single line comments by having the first and last lines
the same. Selecting a different starting line turns this into a multiline comment.