Use Qt Linguist

Most of the text to translate in an application consists of either single words or short phrases. These typically appear as window titles, menu items, tooltips, and labels to buttons, checkboxes, and radio buttons.

You mark the phrases as translatable in the QML and C++ source code. Qt localization tools provide context information for each of the phrases to help the translator understand their meaning. You can add comments to the phrases.

Translation files contain all the user-visible text and keyboard shortcuts in an application and translations of that text.

When you create a new project, you can automatically generate a translation source file (TS) for one language. To add other languages, edit the project file or go to File > New File.

To open TS files in Qt Linguist, right-click a TS file in the Projects or File System view and go to Open With > Qt Linguist in the context menu.