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P4 for Visual Studio Documentation | 2025.2

# P4 - Diff/Merge/Reviews

To set the default diff application, select one of the following:

- P4 Merge: The P4 companion diff tool.
- Other application: Browse to your preferred diff tool.

To specify arguments for third-party diff applications, enter `%1` for the name of the first file and `%2` for the name of the second file in the Arguments field. P4 Server replaces these placeholders with the actual filenames when calling the diff application.

To set the default merge application, select one of the following:

- P4 Merge: The P4 companion merge tool.
- Other application: Browse to your preferred merge tool.

To specify arguments for third-party merge applications, enter the following replaceable parameters in the Arguments field:

- Base file: `%b`
- Their/Source file: `%1`
- Your/Target file: `%2`
- Result file: `%r`

P4 Server replaces these placeholders with the actual filenames when calling the merge application.

[P4VS-2769] To have P4 Code Review reviews open in an external browser (instead of in a new tab in Microsoft Visual Studio, which is the default):

- Select the Open P4 Code Review reviews in external browser check box.

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