As a web developer, how do you take advantage of efficient revalidation? The browser automatically detects if a validation token has been previously specified, it appends the validation token to an outgoing request, and it updates the cache timestamps as necessary based on the received response from the server.The only thing left to do is to ensure that the server is providing the necessary ETag tokens.All modern browsers support Cache-Control, so that's all you need."no-cache" indicates that the returned response can't be used to satisfy a subsequent request to the same URL without first checking with the server if the response has changed.Check your server documentation for the necessary configuration flags.
Assume that 120 seconds have passed since the initial fetch and the browser has initiated a new request for the same resource.
The client doesn't need to know how the fingerprint is generated; it only needs to send it to the server on the next request.
If the fingerprint is still the same, then the resource hasn't changed and you can skip the download.
Find your favorite server in the list, look for the appropriate settings, and copy/confirm that your server is configured with the recommended settings.
From a performance optimization perspective, the best request is a request that doesn't need to communicate with the server: a local copy of the response allows you to eliminate all network latency and avoid data charges for the data transfer.