HTTP status changed: when a page turns into a 404, 500 or redirect

In brief

The HTTP status returned by the page changed: a 4xx/5xx error drops it from the index and cuts its traffic, a 3xx makes it redirect. Identify the cause (deploy, deleted route, server) and restore the 200, or set up a clean 301 redirect.

CriticalP0 — Deindexing

What is it?

The page's HTTP status code changed (e.g. 200 to 404, 500 or a redirect).

Why it hurts SEO and AI

A repeated 4xx/5xx error gets the page dropped from the index and cuts its traffic. LLMs that re-visit the page to cite it get an error and exclude it from their answers.

When it is NOT a problem

  • The 301 redirect is intentional, points to an equivalent page, and the URL was removed from the sitemap (clean removal).
  • You returned a deliberate 410 to signal a permanent, intended deletion.
  • You are on the first crawl of the page: Seogard has no baseline to compare against yet.
Before
GET /category/shoes HTTP/1.1
-> HTTP/1.1 500 Internal Server Error
After
GET /category/shoes HTTP/1.1
-> HTTP/1.1 200 OK

A repeated 500 or 404 drops the page from the index; the goal is to restore a 200, or a clean 301 if the URL should disappear.

How to fix it

  1. Reproduce the request on the affected URL (curl -I or the Network tab) to confirm the status the server returns.
  2. Identify the cause: recent deploy, deleted route, database, or application error.
  3. Restore a 200 if the page should live, or set a 301 redirect to the closest equivalent if it should go away.
  4. Re-crawl the page to confirm the status is back to normal.

This scan checks the HTTP status, noindex and canonical of every page

Is this issue on your site?

Is one of your pages suddenly returning an error? Enter a URL: Seogard checks the real HTTP status of every page and alerts you the moment a 200 flips to a 404, 500 or redirect. Free, no credit card.

By clicking Scan, I certify that I own this site or have permission to crawl it.

  • No credit card
  • Result in ~30 s

What you get back

Google and AI systems keep accessing the content; the URL's accumulated authority is preserved.

Seogard catches this regression automatically — through its monitoring for your metas and canonicals.

Frequently asked questions

Does a 404 make a page lose its rankings?

Yes if the error persists: Google eventually deindexes the URL and its traffic disappears. A quick fix or a 301 redirect preserves the accumulated authority.

What is the SEO difference between a 4xx and a 5xx error?

A 4xx (like 404) says the page does not exist; a 5xx says the server crashed. Both are serious, but a repeated 5xx can also slow the crawl of your whole site.

Related rules

Noindex addedA noindex directive was added (robots/googlebot meta tag or X-Robots-Tag HTTP header). The page will disappear from Google results within days. Canonical missingThe canonical tag is gone. Duplicate content risk — Google no longer knows which URL to index. Canonical changedThe canonical tag points to a different URL. May be intentional (migration) or accidental.

Updated July 10, 2026