Do 404 errors affect your website's SEO?

The short answer: a 404 is not a penalty. Google expects some pages to disappear, and a handful of 404s is normal and healthy. The problem is not the 404 itself, it is what points to it and what you lose when it happens without a plan.

When a 404 is harmless

A page that never had traffic, links or purpose can return a 404 without consequence. Google removes it from the index and moves on. Forcing a redirect for every deleted page creates more clutter than it solves.

When a 404 does cost you

• Broken internal links: if your own navigation, articles or menus point to a 404, you waste crawl budget and send users to dead ends. This is the most common and most fixable issue.
• Lost backlinks: if an external site links to a URL that now 404s, the authority that link carried is thrown away. Those are the ones worth a 301 to the closest relevant page.
• URLs with traffic or rankings: deleting a page that still earns visits or ranks, without redirecting it, discards equity you already paid for.

Soft 404: the silent one

A soft 404 is worse than a real one: the page returns a 200 status but has no real content, so Google treats it as an error without you noticing. Thin pages, empty search results and broken templates cause it. These need real content or a proper status code.

What to do

1. Audit broken internal links and fix them at the source.
2. 301 the deleted URLs that had backlinks, traffic or rankings to the closest relevant page.
3. Let genuinely irrelevant pages 404. Do not mass-redirect everything to the homepage, which Google treats as a soft 404 anyway.
4. Keep a helpful 404 page (search, main links) so users who land on one stay on the site.

How SmartLinks works on this

We treat 404s and redirects as part of technical SEO hygiene, not a one-off cleanup: broken links fixed at the source, equity-bearing URLs redirected on purpose, and a crawl that spends its budget on pages that matter. It is part of our SEO & AI Search work.

If you are migrating a site or blog, this is exactly where equity leaks. The Diagnosis shows where.