Provided is a composition for window films comprising a
siloxane resin of formula 1, a crosslinking agent and an initiator, a flexible window film formed therefrom, and a
flexible display device comprising the same. (R1SiO3 / 2)x(R2SiO3 / 2)y(R3R4SiO2 / 2)z(SiO4 / 2)w (in formula 1, R1 is a functional group containing an alicyclic
epoxy group, R2 is a functional group containing a glycidyl group, R3 and R4 are each independently a
hydrogen, a functional group containing an alicyclic
epoxy group, a functional group containing a glycidyl group, an optionally substituted C1 to C20
alkyl group, an optionally substituted C5 to C20 cycloalkyl group or an optionally substituted C6 to C20
aryl group, wherein 0<x<1, 0<y≤0.5, 0≤z<1, 0≤w<1, and x+y+z+w=1).