Which HTTP status codes should I know?
Practice this questionWANT TO UNDERSTAND THE CONCEPT FIRST?Learn Which HTTP status codes should I know?
Definition:
An HTTP status code describes the outcome of an HTTP request using a standard numeric category. Clients use it to decide whether to use a result, correct a request, authenticate or retry. A response body can add application details, but should not contradict the status code.
Key points:
-
200: success;201: created;204: success without a response body. -
400: bad request;401: missing/invalid authentication;403: not allowed;404: not found. -
409: conflict;429: too many requests;500: server error;503: unavailable. -
Do not return 200 for every failure; clients, monitoring and retry logic then lose useful information.
Interview point:
- Distinguish 401 from 403 and explain that 5xx retries still need limits and safe request semantics.
Adapted from 02_NODE_EXPRESS_HTTP.md · “Which HTTP status codes should I know?”. Code examples are study fragments. Difficulty and core labels are editorial estimates; version-specific behavior should be checked against your project.