We run into problems with words like this- seax and the related scramasax span a thousand years, You can find a lot of variation.
extant examples range from a couple inches to a coule feet. An earlier period langseax would be broader and heavier - more like a long KSA than a later period, which becomes more swordlike.
There is a lot of room for interpretation with this much history and geographical breadth. Which makes it fun
do you need a scandinavian short sword? Well.... I know my answer, the first one is hanging on the wall, but i am working on a better one, in fits and starts as i have time. I'll probably finish mine when I have some orders in for them