it worked. thanks @VRonin

Yes I use the builtin Qt zlib Thank you @ambershark I have added the following line in the quazip project .pro : LIBS += -lz Now I can compile it.

@mrjj Solve the problem loading the data is this way. QDataStream out(&dstFile); out.writeRawData(ba.data(), ba.size()); And works like a charm! Thank you!