Updating your Xcode project configuration file format
Configure your Xcode project to use the JSON project configuration file format that’s more human-readable and editable by coding intelligence agents.
Overview
An Xcode project file with a .xcodeproj extension contains a project configuration file along with other files specific to your project. In previous Xcode releases, a project configuration file is a property list file with a .pbxproj extension. In Xcode 27.2 and later, the default project configuration file is a smaller, hierarchical, self-describing JSON file with a .xcproj extension. Xcode 27 and later supports both file formats so you can choose the format you prefer. For projects you created using earlier releases, you can switch to the new JSON file format.
The open source JSON file format makes verifying project configuration changes easier when committing the project configuration file to your source code repository because changes in the comparison view correspond to your actions in Xcode. Additionally, merge conflicts are less likely because the JSON file format isolates configuration changes. The JSON file format also makes it easier for coding intelligence agents to edit the file for you.
For more information on creating projects, see Creating an Xcode project for an app. For more information on using agents, see Writing code with intelligence in Xcode.
Change the project configuration file format to JSON
In the Project navigator, select the project, and in the File inspector, choose JSON from the Project Format pop-up menu under Project Document. If a dialog appears, click Continue to change the format.
The project configuration file inside the Xcode project (.xcodeproj), changes from a property list file with a .pbxproj extension to a JSON file with a .xcproj extension.
If you use source control, you can undo the file format change by discarding changes to individual files in the Xcode project folder (removal of the file with a .pbxproj and addition of the file with a .xcproj extension).