Nostalgia is not always negative, and I didn't mean to imply that it needs to be replaced. Everyone knows that the icon stands for "Save" even if they don't kno

Nostalgia is not always negative, and I didn't mean to imply that it needs to be replaced. Everyone knows that the icon stands for "Save" even if they don't know where it came from. In a recent tweet from Japan, younger people wonder why the "Save" button in Excel is a vending machine with a drink in the tray. Another popular tweet shows a child wondering why their parents 3D printed a save button. In both cases, they understood the icon stood for save without knowing what it was. As for your question, I would either use a circle with an arrow in it or an open box with an arrow in it. Perhaps a cloud with an arrow if it's saving to the cloud. Another alternative is a bookmark style icon (but then you need to ask: will the future generations experience physical books at all?) However, I'm not a UI/UX expert, and this might clash with the Download button, so you'd have to ask whether or not the distinction is important in your own application. Keeping the convention of a mysterious floppy disk might still be the right choice.