Which headers can potentially allow a resource to be loaded from cache?
Cache-control is an HTTP header used to specify browser caching policies in both client requests and server responses. Policies include how a resource is cached, where it’s cached and its maximum age before expiring (i.e., time to live).
What is Max-age in cache control header?
max-age. The max-age directive states the maximum amount of time in seconds that fetched responses are allowed to be used again (from the time when a request is made). For instance, max-age=90 indicates that an asset can be reused (remains in the browser cache) for the next 90 seconds.
How do I view Pragma headers?
To check the Pragma in action go to Inspect Element -> Network check the header for Pragma like below. Pragma header is highlighted.
What are the different types of cache headers?
Two main types of cache headers, cache-control and expires , define the caching characteristics for your resources. Typically, cache-control is considered a more modern and flexible approach than expires, but both headers can be used simultaneously.
What do you need to know about HTTP caching?
HTTP Caching 1 Enabling Caching. Caching works by categorizing certain page resources in terms of how frequently or infrequently they change. 2 Cache Headers. Two main types of cache headers, cache-control and expires , define the caching characteristics for your resources. 3 Summary.
When to use the Expires header in caching?
The expires header just sets a time in the future when the content should expire. After that point, requests for the content must go back to the original server. With the newer and more flexible cache-control header, the expires header is often used as a fallback.
What are the two primary response headers for caching?
There are two primary response headers responsible for specifying how long the content stays in the cache. a. The Expires header It is used to define an absolute time after which the content should no longer be considered valid for caching. b. The Cache-Control max-age directive