404 Error: Definition & Why It Matters for Ecommerce SEO

Quick definition

The HTTP status code for "page not found." Bulk 404s waste crawl budget and bleed link equity from any links pointing at the dead URL.

404 Error in plain English

When a URL doesn't exist (or doesn't exist anymore), the right response is HTTP 404 — Not Found. This tells browsers, search engines, and anyone clicking a link that the resource isn't here. Search engines will eventually remove the URL from their index. Browsers will show their default not-found UI (or your custom-styled 404 page).

A site with occasional 404s is normal and expected (a typo'd URL, an old social post linking to a removed product, a crawler trying invented paths). A site with hundreds or thousands of 404s in Search Console means something structural is broken: a sitemap pointing at dead URLs, an internal navigation menu linking to removed categories, JavaScript building URLs from a stale product list, or a CMS migration that broke URL handles wholesale.

There's also "soft 404" — a URL that returns HTTP 200 (success) but shows a page that says "page not found" or that's so empty it gives the same impression. Google detects these and reports them in Search Console separately. Soft 404s are worse than clean 404s because Google may continue crawling them, wasting budget, and may not remove them from the index promptly.

The fix flow: check Search Console → Indexing → Pages → Not found (404). For each cluster of 404s, identify the source. If they should still exist, fix the broken link or 301 them to the right URL. If they shouldn't exist (genuinely removed content with no successor), leave them as 404 — Google will deindex them over time. Custom-style your 404 page to help users recover (search box, popular products, link to top categories) — this catches the user even if the URL fails.

Why 404 error matters for ecommerce

For ecommerce, the most common 404 cause is products being deleted from the catalog without redirect handling. Each deleted product was potentially ranking, attracting clicks, accumulating link equity — all of which evaporates the moment the URL 404s. Discipline: every product removal triggers a redirect decision. Replace with a similar product? 301 there. Discontinued with no replacement? Build a category page redirect or accept the clean 404. Bulk deletes without this discipline are the silent SEO killer of mature stores.

Frequently asked questions

How many 404s are too many for a healthy site?

There's no fixed threshold — what matters is what's causing them. A site with 50,000 URLs and 200 random 404s from old links is fine. A site with 1,000 URLs and 200 404s probably has a structural issue (broken internal navigation, sitemap mismatch). Search Console shows trend data — a spike in 404s is the signal, not the absolute count.

Will 404s hurt my rankings?

Not directly. Google has stated 404s on URLs that genuinely don't exist anymore have no negative SEO impact. The damage comes indirectly: link equity from inbound links to 404'd URLs is wasted (would have flowed to a redirect), crawl budget is spent on dead URLs that could have been spent on important pages, and users hitting 404s bounce, hurting engagement signals. The page itself isn't penalized — but the missed opportunity has cost.

What's the difference between 404 and 410?

404 means "not found, no further information." 410 means "gone permanently, don't come back." Google treats both similarly, but 410 is a slightly stronger signal for faster deindexing. For URLs you're certain will never return (discontinued product lines, retired blog content), 410 can speed up cleanup. For most cases, 404 is fine — Google will deindex either way.

Does my custom 404 page need to return status 404?

Yes. The status code is invisible to users but critical for crawlers. A pretty 'page not found' page that returns HTTP 200 is a soft 404 — Google may not deindex it, may continue crawling it, and treats it as low-quality content. Check with curl -I to confirm: curl -I https://yoursite.com/nonexistent should return HTTP/2 404.

Should I redirect every 404 to the homepage?

No — this creates soft 404s (Google sees the homepage doesn't satisfy the user's expectation of the requested URL). The exception is brand-new URLs that were never indexed. For 404s on URLs that previously existed and accumulated equity, 301 to the most relevant alternative page (related category, replacement product, parent collection). For URLs that should genuinely not exist, leave them as clean 404s.

404 Error

404 Error in plain English

Why 404 error matters for ecommerce

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404 Error vs Sitemap.xml: What's the Difference?

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