pyside6-qmlcachegen is a command line tool that wraps qmlcachegen. This tool creates C++ code or QML byte code for .qml files. For Qt for Python, only QML byte code is relevant. The file suffix is .qmlc and it works similar to compiled Python bytecode (.pyc files).


The command line option --only-bytecode should be used to create QML byte code. For example:

qmlcachegen --only-bytecode gallery.qml

produces a file gallery.qmlc containing QML byte code which is automatically loaded by the QML engine.