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HTTP status codes for software support

An HTTP status code is the server’s short answer to a browser or API request. In software support, codes such as 401, 403, 404, 429, and 5xx help you decide whether the problem looks like authentication, permissions, a missing resource, rate limiting, or a server-side failure.

By Tom Ulman · Published · Last reviewed

Why status codes matter in support

When a customer says “the page is broken” or “the integration failed,” the Network panel or API response often includes a status code. That number is a fast way to choose the next check: login, permissions, missing resource, rate limit, or server-side failure. You do not need every MDN code memorised—you need the ones that show up in SaaS tickets.

A practical support map

CodePlain meaningSupport next step
200–299Request succeededIf the UI still looks wrong, look at the response body or a later request
401Not authenticated / credential invalidSession expired, bad token, missing Authorization header
403Authenticated, not allowedRole, plan, org, or feature flag—confirm identity first
404Resource not foundWrong ID, deleted object, or wrong environment/URL
429Too many requestsRate limit—check retries, burst traffic, or plan limits
500–599Server-side failureReproduce, capture request ID/HAR, escalate with evidence

Example: login loop vs permission error

A customer cannot open Billing. DevTools shows GET /api/billing → 401 then a redirect to login. That is usually an auth/session problem. If the same call returns 403 while other APIs return 200 for the same user, investigate role or plan access instead of “password reset.”

Common mistakes

  • Treating every red Network row as a product bug—extensions and third-party scripts fail too.
  • Confusing 401 and 403; the fix path is different.
  • Ignoring a successful 200 that returns an error payload in JSON.

How to capture the code cleanly

  1. Reproduce in a clean browser profile when you can.
  2. Open DevTools → Network, reproduce once, find the failing request.
  3. Record status, URL, method, and any request ID. See Chrome DevTools for software support.

For the scenario walkthrough of a failing API call, use the guide Troubleshoot an API request in support.

Related concepts

Primary sources

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