You don't need to pay at all. Comparison is here: https://www.qt.io/download https://www.qt.io/download Basically, you need to link dynamically or provide obje

You don't need to pay at all. Comparison is here: https://www.qt.io/download https://www.qt.io/download Basically, you need to link dynamically or provide object files. You can't use commercial modules too. But that's only a small portion of Qt anyway.