Achieving the Paris Agreement 1.5°C target requires a reversal of the growing atmospheric concentrations of methane, which is about 80 times more potent than CO2 on a 20-year timescale. The IPCC 6th Assessment Report stated that methane is underregulated but little is known about the effectiveness of existing methane policies. In this Review, we systematically examine existing methane policies across the energy, waste and agriculture sectors. We find that currently only about 13% of methane emissions is covered by methane mitigation policies. Moreover, the effectiveness of these policies is far from clear mainly because methane emissions are largely calculated using potentially unrepresentative estimates instead of direct measurements. Coverage and stringency are two major blind spots in global methane policies. These findings suggest that significant and underexplored mitigation opportunities exist but unlocking them requires policymakers to identify a consistent approach for accurate quantification of methane emissions sources alongside greater policy stringency.