What HTTP response headers are required

Question

What HTTP response headers are required to be sent from server to the client?

I working to optimize the HTTP response headers to minimize the HTTP response overhead.

Answer 1

It depends on the specifics of the response, but generally, a response from an origin server should have:

• Date
• Content-Type
• Server

and either Content-Length, Transfer-Encoding or Connection: close.

If you want to do caching, add Cache-Control (e.g., with max-age); Expires isn't generally necessary any more. If you want clients to be able to validate, add Last-Modified or ETag.