Set cache expiry headers and estimate the repeat-visit saving.
Long cache lifetimes are only safe when filenames change with content, which is what build-time hashing provides. With hashing, a one-year max-age is the standard recommendation. Caching is the cheapest performance win available, because repeat visitors download nothing at all for unchanged assets.
Browser Cache Expiry
Bandwidth saved = repeat visits × cacheable weight; max-age is expressed in seconds
Bandwidth saved = repeat visits × cacheable weight; max-age is expressed in seconds Long cache lifetimes are only safe when filenames change with content, which is what build-time hashing provides. With hashing, a one-year max-age is the standard recommendation.
Caching is the cheapest performance win available, because repeat visitors download nothing at all for unchanged assets.
This calculator takes 5 inputs: Cacheable asset weight, Cache max-age, Share of visits that are repeat, Monthly visits, Connection speed. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.