Disclosure: This article was generated with AI from a documented site audit. The code and paths below are simplified examples, not private repository excerpts.

A path in a 404 report can look close enough to a real route that your first instinct is to redirect it. On HandMen’s German-language guide site, the reported paths looked like existing pages with -1 or -2 tacked onto the end. The useful clue was not a missing route or a breadcrumb link. It was a URL-shaped string emitted as a React list key.

The distinction mattered: the team could remove the string at its source without redirecting a page that had never been shown to exist.

Look for a route, a link, and a string separately

Take one reported URL and one plausible source page. If the report shows a referring page, treat it as a starting point, not a complete record of how the URL was discovered.

  1. Request the two paths. Is the intended route live, and does the suspicious variant actually return 404? Check the response status as well as what the page looks like.
  2. Check navigation targets. On the candidate source page, inspect actual anchor destinations in the response and in the rendered DOM. Google’s crawlable-link guide explains why an anchor with an href is the relevant comparison. A substring search alone cannot establish that a matching link exists.
  3. Search for the full variant in the response. Note where the match occurs: an anchor, canonical, hreflang, structured data, or a serialized payload. Check the sitemap separately. A string in a payload and a visible navigation link are different findings.

In the HandMen audit, 186 of the reported variants matched breadcrumb keys in serialized output. None of those matches was a corresponding breadcrumb href. A separate reported path came from template data and needed a different diagnosis. This establishes where the strings appeared in the output that was examined. It does not prove what Google used to discover them.

Keep the key separate from the destination

Here is a simplified version of the pattern. Suppose item.href is /guides/flooring and the item is at position 2:

// The destination is /guides/flooring. // The key can become /guides/flooring-2. items.map((item, index) => ( <li key={`${item.href}-${index}`}> <a href={item.href}>{item.label}</a> </li> ));

A key is React bookkeeping, not an anchor attribute. In this case the page’s rendering pipeline exposed the key in serialized output. Don’t assume every React application serializes keys the same way: inspect what your build actually serves.

At this site, breadcrumb paths were already stable and unique among siblings, so the fix removed the positional suffix:

items.map((item) => ( <li key={item.href}> <a href={item.href}>{item.label}</a> </li> ));

If a breadcrumb can repeat the same destination, use an explicit, stable identifier from the data instead. React’s list rendering documentation explains the sibling-uniqueness and stability requirements.

Verify the fix in the response, not just in the component

For a regression check, compare the same suspect strings with the rendered link destinations before and after deployment. In the November 10 production check, the team sampled 12 pages across guide listings, articles, and illustrative project pages. The sampled real routes still responded with HTTP 200, the suffix strings were absent from those pages, canonical targets remained correct, and intentional noindex directives on the example pages stayed in place.

That is a deployment check, not a Search Console outcome. We did not establish when the report would clear or whether any ranking changed. If a flagged URL has no real page or useful replacement, don’t create a redirect merely to make the report shorter. Fix the generator first; add a redirect only when you have evidence of an actual URL move or a relevant replacement.