Merging files
P4Merge enables you to
compare two text files with a common base file to locate differences and
to select the text that you want in the merged result file. The purple
icon () is associated with the
file that another user edited (their file), and purple
bands highlight text that is unique to that file. The green icon (
) is associated with file
that you edited (your file), and green bands highlight
text that is in the second file but not the first file. The base file is indicated by the yellow icon (
), and yellow
highlighting indicates text that is in the base file but not in the other
files.
In the top half of the window, P4Merge displays the base file surrounded by the two changed versions of the revision being merged. In the bottom half of the window, P4Merge displays the merge results file, where you select or enter the text that you want to check in. Make your changes as described below, and be sure to save them before exiting P4Merge.
For information on merging files from within P4V, see Merging files and Resolving files in the Helix Core Visual Client (P4V) Documentation.
To merge files:
- Go to File > New Merge or Diff.
-
In the Choose Files dialog box, on the Merge tab, specify the base file and the two files to be merged.
-
Click OK.
P4Merge shows each file in its own pane, with the base file in the middle. The bottom pane shows the merge results file, a consolidated, merged version of all files.
Navigate diffs
To move forward and back through individual differences, or to locate specific text or lines, click the toolbar buttons listed below.
Go to next diff |
![]() |
Go to previous diff |
![]() |
Find text |
![]() |
Go to line number |
![]() |
Merge text
To merge files, you can either choose text from one of the files or enter changes directly into the merge results file.
Choose Text Chunks
To choose the entire contents of a file, click the corresponding icon in the merge diagram, as shown below.

To choose a single chunk of text from a set of diffs, click the corresponding button to the right of the chunk, as shown below.
The buttons indicate the origin of the text and the way it was changed, as follows:
![]() |
Base file text |
![]() |
Same in theirs and base. |
![]() |
Same in yours and base. |
![]() |
Text added to their file. Not in yours or base. |
![]() |
Text added to your file. Not in theirs or base. |
|
Text deleted from their file. |
![]() |
Text deleted from your file. |
![]() |
Same in yours and theirs, different from base. |
![]() |
Added to both yours and theirs. |
![]() |
Deleted from both yours and theirs. |
Note that these are toggle buttons: click once to select the corresponding text, click again to deselect it.
If P4Merge encounters too many changes to display all the required
buttons, it displays this button: . Click it to view the
details.
If you are working with large text files, see the Support Knowledgebase article, Improving diff results when comparing files with more than 50,000 lines.
Syntax highlighting is available (starting with version 2020.2). Click the Show Syntax Highlighting button to toggle the feature on or off.
More than 300 languages supported languages are listed at https://kate-editor.org/syntax/.
Edit text
To edit the text in the merge result file, click on the text in the bottom pane and enter your changes. Manually edited text is displayed with a gray highlight, like the middle chunk in the following example: