Module 11
HTTP
The conversation behind every web page. Build requests, read status codes and headers, and see how connections and caches cut the waiting.
Start lesson 1
What is in a request and a response? · 8 min · free, no account
ApplicationOpen now
What you'll operate
- Requests and responses
- Methods and status codes
- Connections and caching
- lessons
- 6
- minutes
- 51
Lessons in this module
- 1What is in a request and a response?Read an HTTP request and its response line by line, and spot the request a server must refuse.Free, no account8 min
- 2Which method, and can it be sent twice?Choose the right method for a job, and decide when a request that got no answer may be repeated.Plus8 min
- 3What is the server telling you?Read a status code by its first digit, then tell apart the pairs that get confused: 401 and 403, 502 and 504.Plus8 min
- 4Which site, and how many connections?See how one address serves many sites, and how HTTP/1.1, HTTP/2 and HTTP/3 fit a page's requests onto connections.Plus9 min
- 5Can this copy be reused?Decide when a stored response may be reused, when it must be checked, and what a 304 saves.Plus9 min
- 6Who answered, and how did it know you?Follow a redirect, see how a cookie adds memory to a protocol that has none, and find out what a proxy or CDN changes.Plus9 min
Lesson 1 is open to everyone, with no account. The other lessons in this module are part of Plus.