Much of the benefit of stale-while-revalidate was already available prior to any browsers supporting it. Your CDN probably supports it already. Set to an approp

Much of the benefit of stale-while-revalidate was already available prior to any browsers supporting it. Your CDN probably supports it already. Set to an appropriate value, you can keep CDN content fresh while letting end users never get a cache miss. This cache-control directive isn't new, but I'm still excited about it, especially together with stale-if-error.