Enables the directed movement of pyridoxal across a membrane into, out of or within a cell, or between cells. Pyridoxal, 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarboxaldehyde, is one of the vitamin B6 compounds. Pyridoxal, pyridoxamine and pyridoxine are collectively known as vitamin B6, and are efficiently converted to the biologically active form of vitamin B6, pyridoxal phosphate.