darn, i know this and i forgot

 

what is the difference between keyblades with keychains and keyblades with out keychains?

They are the same thing.

wasnt the reason that terra aqua and vens keyblades did not have keychains in the secret kh2 ending because they were still devolping the game

yea i know random

My guess is, that all keyblades looks the same, but the keychain make them change shapes and forms.

i think its the samething

same thing changes abilities and lenght and st00fz >.

There is no difference. Keychains are the memories of past keyblades.

Keychains are what transform Keyblades, Otherwise Sora wouldn't have room for all those keyblades. I read a rumor once, i think it was on the KH wiki let me see....

 

Ahh here it is

Sora's Keyblade is known as the "Keyblade of Worlds' Hearts"[citation needed], and nearly all of his Keychain tokens represent some important item from a world he has saved. Usually, Sora is not actually shown to be given the Keychain from one of his many friends, so it is possible that after saving a world, or completing a major step in that direction, the world itself rewards him with the ability to access its power in the form of a unique Keychain.

Keychains that Sora receives from his friends, or from defeating challengers in the Olympus Coliseum, always use a token that is somehow intimately symbolic of that person. While Sora's Keyblade is not specifically a Keyblade of human hearts, like the explicitly named Keyblade of People's Hearts, it is likely that the connections between his heart and those he meets allow him to sometimes access their power as well. Sora and Roxas's Oathkeeper and Oblivion are said to specifically embody Sora's memories of Kairi and Riku and Roxas's oath to Xion before her death (Oathkeeper) as well as her demise (Oblivion) and so it is extremely likely that for "people-Keyblades" like these, the Keychains act as a physical embodiment of the memories Sora and Roxas has of those that are important to them.

its the same thing it just gives keyblade a different look

I always thought that the keychains made the keyblade stronger and connects the keyblade-wielder to the world that he/she has saved.