TECH LITTLE BRAWTAGLOBAL TECHNOLOGY NEWSROOM & LEARNING
LESSON 4 OF 4 / 8 MINUTES

When can a stored response be reused?

Your objectiveDistinguish cache storage from validation before reuse.

Understand the idea.

The decision to keep a response and the decision to reuse it are separate. no-store tells caches not to retain the response. no-cache allows storage but requires validation before reuse. A private response must not be stored by a shared cache, although a private browser cache can still be permitted to store it.

MAKE IT CONCRETE

A worked example.

A versioned stylesheet and an editor’s authenticated page should not automatically share the same policy. A stylesheet whose URL changes with its bytes can tolerate different reuse rules from an editing response that contains private state.

Try the reasoning.

Read the Cache-Control header on this local page. Use the Blog explainer to compare that value with no-cache. Do not change browser or network security settings.

A SIMPLIFIED REQUEST JOURNEY

DNS supplies records associated with the name. A successful answer does not establish application health.

Conceptual illustration. Selecting a step does not send a network request.
Which directive permits storage but requires validation before reuse?

Carry it into practice.

Create a two-column inventory: resources that may be stored, and the conditions under which each may be reused.

Read the reference: MDN: Cache-Control ↗