There is a Doxygen generated documentation based on Qt 4.8.6 sources.

It is an alternative to the documentation generated with QDoc.

Yes, it is a little bit bugged, because Doxygen is not fully supported the Qt commenting style and all Qt tags.

However, it could be useful if you want to see inside the Qt 4.8.6 sources.

Just use https://dreamswork.github.io/qt4/ for accessing the documentation.

Note: The documentation is not included 3rd party sources, Qt tools, Qt3Support API (deprecated) and Symbian S60 parts (already not useful).