TeamCity Difference Viewer allows reviewing the differences between two versions of a file modified in the source control and navigating between these differences. You can access the viewer from almost any place in the TeamCity UI where the changes lists appear, for example, the Projects page, Build Configuration Home Page, or the Changes tab of the build results page. Comparing images in the GIF, PNG or JPG file formats are also supported.
Clicking the name of a modified file opens the viewer:
The window heading displays the file modifications summary:
the file name along with its status,
the changes author,
the comment on the changes list.
To move between changes, use the next and previous change arrows and the red and green bars on the versions separator.
If you want to switch to your IDE and explore a change in detail, click the Open in the IDE button in the upper-right corner of the window or select it in the pop-up next to the file name. The file opens, and you will navigate to this particular change.