  The Galois representations associated to weight $1$ newforms over
$\bar{\mathbb{F}}_p$ are remarkable in that they are unramified at $p$, but the
computation of weight $1$ modular forms has proven to be difficult. One
complication in this setting is that a weight $1$ cusp form over
$\bar{\mathbb{F}}_p$ need not arise from reducing a weight $1$ cusp form over
$\bar{\mathbb{Q}}$. In this article we propose a unified "Hecke stability
method" for computing spaces of weight $1$ modular forms of a given level in
all characteristics simultaneously. Our main theorems outline conditions under
which a finite-dimensional Hecke module of ratios of modular forms must consist
of genuine modular forms. We conclude with some applications of the Hecke
stability method motivated by the refined inverse Galois problem.
