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Learn HTTP

A method and URI express intent. Status, headers and content express the outcome.

3 sections · 10 explained questions · About 10 minutesAll lessons →

Read each short explanation, work through the example, then answer a pop quiz. Every answer explains the reasoning. Incorrect answers unlock a fresh question on the same idea; the full lesson contains ten questions.

01Understand the basics

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Hypertext Transfer Protocol (HTTP) carries requests and responses. The method describes the action, the URL identifies the target, headers carry metadata, and the body can carry content. A status code describes the outcome; read the specific code and response details together.

Section 1 question · 4 variations
What does 401 mean?

02Interpret responses

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Status classes group outcomes: 2xx success, 3xx redirection, 4xx client errors and 5xx server errors. Different codes within a class require different handling.

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Request2xx successInterpret specific status
Section 2 question · 3 variations
Which response indicates rate limiting?

03Retry with care

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Idempotent means repeating the same request has the same intended effect as making it once. GET, PUT and DELETE have idempotent semantics. Response codes may still differ between attempts.

Section 3 question · 3 variations
Which statement about DELETE is correct?

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