This paper deals with Strauss and Lions-type theorems for fractional Sobolev spaces variable exponent $$W^{s,p(.),{\tilde{p}}(.,.)} (\Omega )$$ , when p $${\tilde{p}}$$ satisfy some conditions. As application, we study the existence of solutions a class Kirchhoff–Choquard problem in $${\mathbb {R}}^N$$ .