A katana is considered a long sword. In the realm of sword classification, the term "long sword" typically refers to a one-handed or hand-and-a-half sword with an extended blade length. The katana fits this description as it possesses a longer blade compared to shorter swords like daggers or shortswords.

The blade length of a katana typically ranges from around 60 to 80 centimeters (24 to 31 inches), with the total length of the sword (blade plus handle) ranging from approximately 100 to 110 centimeters (39 to 43 inches). This longer blade provides advantages in terms of reach and cutting power.

While there are longer two-handed swords, such as greatswords or claymores, the katana is considered a long sword within the context of one-handed or hand-and-a-half swords. It strikes a balance between reach, maneuverability, and versatility.

It's important to note that the categorization of a sword as "long" or "short" can be subjective and may vary depending on the context of comparison. Compared to shorter blades like knives or daggers, a katana would be considered long. However, when compared to polearms or larger two-handed swords, the katana might be considered relatively shorter.

In summary, the katana is generally classified as a long sword due to its extended blade length and overall size within the realm of one-handed or hand-and-a-half swords.