Do I seal just the grout lines or the whole granite tile surface area?
With natural stone I seal everything. With glazed tiles I usually only seal the grout lines because the tile glaze is a sealer so putting additional sealer won’t add protection and in some cases can change the color or surface shine of the tile.

So glazed and porcelain I do the grout lines natural stone I seal the stone &amp; grout because both are porous.