Networking & HTTP·Networking from DNS to production

Headers and caching

Read content types, cache directives and conditional requests.

Beginner 14 min read Lesson 5 of 300 Challenge included

What you will be able to do

Set Content-Type correctly.
Use Cache-Control: public, max-age with immutable for hashed assets.
Use no-store for private data.
Use ETag for revalidation.

In plain English

Headers carry metadata: Content-Type, Content-Length, Cache-Control, ETag and Authorization. Cache-Control tells browsers and CDNs what they may store. Conditional requests with ETag or If-None-Match avoid re-sending unchanged content.

headers.httpHTTP

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Cache-Control: public, max-age=60, stale-while-revalidate=300
ETag: "v1-abc"
Vary: Accept-Encoding

Your turn

Cache a hashed asset

Easy

Write a Cache-Control value for an immutable hashed asset.

HTTP · starter

Cache-Control:

Check your understanding before moving on.

Knowledge checkQuestion 1

Which directive prevents a response from being cached?

Select an answer to continue

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Lesson 5 of 300 · 0% of course