I have fought with many kinds of European blades, from longswords to zweihanders to sabres and foils. Some of these can be very light and thin. In fact, the average longsword weighs the same as the average katana: between 1.1 and 1.5 kg. But I’ll take the length, cross guard and double edge of a longsword over a katana every day.

Source: I practice HEMA