Decode a failed status code

You call an API, get nothing back that makes sense, and you can't tell if the problem is yours or theirs.

BeginnerRead 4 minDoing: 20 to 30 minutes with a terminal open5 steps

▶ Start

What you'll have at the end

A short log of 5 failed calls, each with its actual status code and what it means

Before you start

You need

A command line with an HTTP client already on it, most machines ship with one, and a call you know is currently failing, in your own project or against a public API you're willing to poke at.

Not covered

This does not cover fixing whatever caused the failure or writing code that retries automatically; it only covers reading what the server actually told you.

Leans on

Read what the server actually said

Capture the real status line and headers
Split the code by its first digit
Look up the exact code's real meaning

Handle the tricky ones and keep the record

Check the body when the same code repeats
Log all five calls in one table

Where to go next

Catch an API that always answers 200 on failure

for when the status code itself is the lie: the call answers 200 but the failure is hiding in the body.

Checked 18 Aug 2026

Part of the HTTP cookbook