  Given $L\geq 1$, we discuss the problem of determining the highest
$\alpha=\alpha(L)$ such that any solution to a homogeneous elliptic equation in
divergence form with ellipticity ratio bounded by $L$ is in $C^\alpha_{\rm
loc}$. This problem can be formulated both in the classical and non-local
framework. In the classical case it is known that $\alpha(L)\gtrsim {\rm
exp}(-CL^\beta)$, for some $C, \beta\geq 1$ depending on the dimension $N\geq
3$. We show that in the non-local case, $\alpha(L)\gtrsim L^{-1-\delta}$ for
all $\delta>0$.
