Expires headers were also widely used in the past The stale if error response directive indicates that the cache can reuse a stale response when an upstream server generates an error or when the error is generated locally This means that content remains available even if the server is temporarily unreachable Revalidation doesn x77 t http://jobboard.piasd.org/author/registrationkex312/ mean transferring the entire content again Ask the origin server whether or not the https://paiza.io/projects/iPjX9xNgkbf78It9jz--hw response is still fresh What it does The immutable directive tells the browser that the content of the file will never change so the browser doesn x77 t need to revalidate it even when the user refreshes the page You can cache but you must revalidate with the server before using the cached copy The s maxage response directive indicates how long the response remains fresh in a shared cache Indicates that the response is a stale response Cache storage isn t required http://jobboard.piasd.org/author/clicksvot77/ remove https://paiza.io/projects/PamuwSxY_kt-OR8tcEQIkA responses immediately because revalidation could change the response from being stale to being fresh again You can also track cache hit rates for resources on your website or measure conversion rates to see how performance impacts business results The Cache Control header in HTTP provides precise directives for controlling how and when cached responses are https://paiza.io/projects/jqfDpCvY1_yMv4ub8kMOGA The client indicates that an already cached response should be returned The request waterfall view lists all the resources loaded by your website Cache Control Headers are a powerful tool for controlling how browsers and caches store and serve your website x77 s content For example a request with the header above indicates that the browser will accept a stale response from the cache that https://paiza.io/projects/PN7L9w0sd6X07FyLFGFYAw expired within the last hour https://paiza.io/projects/fMDqyYipP_tJ8S-TY3u6Bg example some convert images to reduce transfer size Cached resources must be validated with the origin server before each reuse even if they haven x77 t expired no cache allows caches to store a response but requires them to revalidate it before reuse When a user requests a resource that is cached the cached copy can be served without hitting the origin server resulting in faster response times and reduced server load This is perfect for https://paiza.io/projects/6u7mUOoA04rtXqsrzBn8OQ that follow the cache https://paiza.io/projects/MZI6TIHTaHsuPocpdDxhdA pattern where each http://jobboard.piasd.org/author/proudlydxz307/ creates a new file with a different name This is why it 8767 s important to balance caching with a strategy to ensure users eventually receive the newest versions of your resources But for now you can simply use no cache instead When to use Apply this header to pages containing personal or sensitive information such as account pages checkout flows or anything containing PII Personally Identifiable Information In the waterfall resources that are loaded from the cache are marked by a cache badge for the https://paiza.io/projects/nCOk31n73lzUSJbOw8DDkQ