We define a category of pure birational motives over a field, depending on the choice
of an adequate equivalence relation on algebraic cycles. It is obtained by “killing” the
Lefschetz motive in the corresponding category of effective motives. For rational
equivalence, it encompasses Bloch’s decomposition of the diagonal. We study the
induced Chow–Künneth decompositions in this category, and establish relationships
with Rost’s cycle modules and the Albanese functor for smooth projective
varieties.