Cache-Control header directives in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Cache-Control header in HTTP?

The Cache-Control header tells browsers and other clients how to store and reuse responses to improve speed and reduce server load.

beginner

What does the directive no-cache mean in Cache-Control?

no-cache means the client must check with the server before using a cached response to make sure it is still fresh.

intermediate

Explain the difference between no-store and no-cache directives.

no-store means do not save the response anywhere, while no-cache means save it but always check with the server before reuse.

beginner

What does the max-age directive specify?

max-age sets the maximum time in seconds that a response can be used from cache without checking the server.

beginner

How does the public directive affect caching?

public means the response can be cached by any cache, even shared ones like proxies.

Which Cache-Control directive forces the client to always validate the cached response with the server before using it?

A no-cache

B no-store

C max-age=3600

D public

no-cache requires validation before reuse.

What does max-age=0 mean in Cache-Control?

A The response can be cached forever

B The response is immediately stale and must be revalidated

C The response should not be cached at all

D The response is private

max-age=0 means the cached response is stale immediately and must be checked with the server.

Which directive prevents storing the response in any cache?

A must-revalidate

B no-cache

C private

D no-store

no-store forbids storing the response anywhere.

If a response has Cache-Control: private, who can cache it?

A Any cache including proxies

B No one can cache it

C Only the browser's private cache

D Only CDN caches

private means only the end user's browser can cache the response.

What does the must-revalidate directive enforce?

A Cached responses must be revalidated after they become stale

B Responses should never be cached

C Cached responses can be used without checking

D Responses are public

must-revalidate means once the cached response is stale, it must be checked with the server before reuse.

Describe the main Cache-Control directives and their effects on caching behavior.

Think about how each directive controls storing, reusing, or validating cached responses.

Explain how Cache-Control headers help improve web performance and user experience.

Consider what happens when browsers reuse cached data correctly.