API Design · Junior · Question 15 of 75

When should an API return `5xx` codes?

1Never; errors should always be 200
✓Correct answer: When the failure is on the server side (bugs, unavailable dependencies), not because of the client's request
3When the client sends invalid data

Explanation

Clients and monitoring treat 4xx as client errors and 5xx as server errors. Returning 200 with an error body hides failures from both.

Further reading

MDN: HTTP response status codes ↗

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