Is Bleach episode 221 filler?
Canon No, episode 221 of Bleach is canon.
#221
The Full Showdown! Soul Reapers vs. Espada
全面対決!死神VS十刃
Aired 26 May 2009
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.