Blow unit for an apparatus (1) for making air-filled bags from a film material (F) having chambers (12), wherein the blow unit (8) comprises a body (26) having an outlet opening (28) for introducing air into the chambers, wherein the blow unit comprises a guiding element (30) for guiding the film material towards the outlet opening, wherein the blow unit (8) comprises an air guiding space (32) that extends from the outlet opening (28) over a distance (D) at least partly along the guiding element, wherein a length (L) of the air guiding space (32) is such that in use, during introducing air into the film material (F), the air guiding space enables introduction of air into two adjacent chambers (12a, 12b) at the same time. The invention further relates to an apparatus comprising such a blow unit, a system comprising such an apparatus and a method for making air-filled bags.