Abstract: The invention relates to a hand welder (1) for welding plastic workpieces by melting a plastic welding filler, comprising a feed device (4) for feeding the welding filler into a melting device (5) for melting the welding filler and to which a welding head (7) with an outlet (58) for the molten welding filler is attached on the outlet side, which is characterised in that the melting device (5) has at least two melting units (24, 25) disposed next to one another, and every melting unit (24, 25) has its own passage channel (38, 39) for the welding filler, the passage channels (38, 39) opening out into a mixing head (6) for mixing the molten welding fillers passing out of the passage channels (38, 39).