Methods and systems in which data formatted according to an air-gapped network protocol is converted to machine-readable optical labels for communication across the air gap. Communication between computer systems across an air gap is facilitated by converting data to one or more machine-readable optical labels and displaying those labels on a first display device coupled to a computer system within an air-gapped network. At another computer system outside the air gapped network, an imaging device receives the machine-readable optical labels displayed on the first display device. The information encoded in the machine-readable optical labels is decoded to recover the original data from the air gapped network and provided to one or more nodes of the non-air-gapped computer network.