Website Health Guides

The SEO Impact of Too Many 404 Errors

Learn when 404 errors hurt SEO, which missing URLs to fix first, when to use 301 redirects, and how to handle sitemap, internal link and backlink 404s.

By CheckDomainHealth Editorial Team Reviewed by Dionis Ceban Updated Jun 28, 2026 10 min read Beginner

Introduction

A 404 error means the requested URL was not found. Some 404s are normal. Users mistype URLs, bots request random paths, and old pages may no longer exist. A small number of 404s does not automatically mean your website has an SEO problem.

The real issue is when important URLs return 404: pages linked internally, pages listed in your sitemap, pages with backlinks, pages that previously received traffic, or URLs that should have been redirected after a migration. Too many important 404s can waste crawl activity, frustrate users and reduce trust.

Quick answer

Quick answer

404 errors are normal for URLs that truly do not exist. They become an SEO problem when important pages, sitemap URLs, internal links, migrated URLs or backlink targets return 404. Fix broken internal links, remove 404s from sitemaps, restore missing pages or add 301 redirects to relevant replacements.

404 errors

A 404 Not Found response tells browsers and search engines that the server could not find the requested URL.

A 404 can happen when:

  • a page was deleted
  • a URL changed
  • a slug was edited
  • a migration missed redirects
  • an internal link is broken
  • a sitemap contains old URLs
  • an external site links to an old page
  • a user mistyped a URL
  • bots request random paths

404 is not always bad. It is the correct response for a URL that does not exist and has no relevant replacement.

Are 404s bad?

404 errors are not automatically bad for SEO. Search engines expect websites to have some missing URLs, especially old or random URLs.

404s become more important when they affect:

  • pages that should exist
  • URLs in your sitemap
  • internal links
  • pages with backlinks
  • pages with traffic
  • migrated URLs
  • product or service pages
  • important guide/blog pages
  • canonical URLs
  • landing pages from ads or campaigns

The question is not “Do I have 404s?” The question is “Are important URLs returning 404?”

Which 404s to fix

High priority

Sitemap URLs returning 404, internal links pointing to 404, important pages accidentally deleted, URLs with backlinks, URLs with organic traffic, old URLs after migration, product/service pages, landing pages from campaigns, canonical URLs returning 404.

Medium priority

Old blog posts with some traffic, category/tag pages used internally, outdated resource pages with relevant replacements, pages shared on social media.

Low priority

Random bot URLs, obvious spam paths, mistyped URLs, deleted pages with no replacement, test URLs never linked internally, URLs blocked intentionally.

Start with 404s that affect real users, internal linking, sitemaps, backlinks or search traffic.

404 vs 410 vs redirect

404 Not Found

  • Use when: The page does not exist and may or may not return later.

410 Gone

  • Use when: The page was intentionally removed and should not return.

301 Redirect

  • Use when: The old URL has a relevant permanent replacement.

Restore page

  • Use when: The URL should still exist and was removed by mistake.

Do not redirect every 404 to the homepage. Irrelevant redirects can create a poor user experience and weak SEO signals.

Migration 404s

After a website move or redesign, 404 errors often happen because old URLs were not mapped to new URLs.

Common migration causes:

  • changed URL slugs
  • removed .html endings
  • changed category paths
  • changed permalink structure
  • moved blog posts
  • deleted product pages
  • changed service page URLs
  • old domain not redirected
  • HTTP/HTTPS or www/non-www rules incomplete
  • sitemap regenerated incorrectly

Before launch, create a redirect map from important old URLs to relevant new URLs.

Why this matters

Why this matters

404 errors matter because they can affect both users and search engines. Users who land on missing pages may leave. Search engines may spend crawl activity on URLs that no longer provide content. Internal broken links can also weaken site quality and make important content harder to discover.

The SEO impact depends on the value of the missing URLs, not just the total number of 404s.

How to find 404s

Use Website Status Checker for individual URLs, then review sitewide sources for patterns.

Check:

  1. Sitemap — confirm sitemap URLs return 200 OK.
  2. Internal links — crawl the site and find links pointing to 404 pages.
  3. Search Console — review indexed or discovered URLs returning Not Found.
  4. Analytics — find landing pages with traffic that return 404.
  5. Backlinks — check important external links pointing to missing URLs.
  6. Migration list — compare old URL list with new URL destinations.
  7. Server logs — find frequently requested 404 URLs.
  8. Campaign URLs — check ad, email and social landing pages.

Check URL status

Use Website Status Checker to test individual URLs and confirm status codes, redirects and final responses.

Run Website Status Check →
Useful checks 
Check one URL:
curl -I https://example.com/missing-page

Follow redirects:
curl -IL https://example.com/old-page

Find internal links with crawl tools:
Crawl website → filter status code 404

Check sitemap URLs:
Export sitemap → test status codes → remove or fix 404 URLs

Server log pattern:
Review most requested 404 URLs and prioritize real user paths.

Command examples are illustrative. Use crawl tools, Search Console, analytics and server logs for complete sitewide analysis.

Common problems

Sitemap contains 404 URLs

High

Search engines are told to crawl URLs that do not exist.

Next step: Remove missing URLs from the sitemap or restore/redirect them.

Internal links point to 404 pages

High

Users and crawlers hit broken links from inside your own site.

Next step: Update internal links to final working URLs.

Old migration URLs return 404

High

Users and search engines cannot find moved content.

Next step: Add 301 redirects to relevant new pages.

Important page deleted by mistake

High

A valuable URL disappeared unexpectedly.

Next step: Restore the page or redirect to a close replacement.

Backlink target returns 404

Medium

External link value and referral users land on a missing page.

Next step: Redirect to the most relevant replacement page.

All 404s redirect to homepage

Medium

Users land on irrelevant content instead of useful replacements.

Next step: Use relevant redirects or keep true 404/410 responses.

Soft 404

Medium

A missing page returns 200 OK with not-found content.

Next step: Return a real 404/410 or redirect to a relevant page.

Custom 404 page missing

Low

Users receive a poor dead-end experience.

Next step: Create a helpful 404 page with search, navigation and popular links.

Deleted product pages have no plan

Medium

Old product URLs may still receive traffic or backlinks.

Next step: Redirect to replacement product, category or return 410 if truly gone.

Bots generate many random 404s

Low

Random invalid URLs may inflate 404 reports.

Next step: Ignore obvious bot noise unless it causes server load or security issues.

How to fix 404s

  1. Step 1: Collect 404 URLs

    Use crawl reports, Search Console, analytics, backlinks and server logs.

  2. Step 2: Prioritize important URLs

    Focus on sitemap URLs, internal links, traffic pages and backlinks first.

  3. Step 3: Decide the correct action

    Restore, redirect, update links, remove from sitemap, return 404 or return 410.

  4. Step 4: Redirect only when relevant

    Use 301 redirects to the closest matching page, not always the homepage.

  5. Step 5: Fix internal links

    Update menus, content links, buttons, breadcrumbs and related posts.

  6. Step 6: Update sitemap

    Include only final canonical 200 URLs.

  7. Step 7: Improve 404 page

    Provide search, navigation, contact and popular pages.

  8. Step 8: Monitor after changes

    Re-check important URLs and review new 404 patterns over time.

404 monitoring checklist

A 404 spike after a redesign or migration usually means the redirect map is incomplete.

Sitemap 404s

Remove or fix URLs listed in sitemap that return 404.

Internal broken links

Update links from menus, content and templates.

Top 404 URLs by hits

Prioritize frequently requested missing URLs.

404s with backlinks

Redirect or restore important external link targets.

404s with organic traffic

Fix pages users still find in search results.

Campaign landing page 404s

Check ad, email and social URLs.

Migration URL 404s

Compare old URL list with redirect map.

Soft 404s

Fix pages that return 200 with missing content.

Recurring bot paths

Ignore noise unless it affects server load.

404 spikes after deployment

Review recent releases and redirect changes.

Deleted product/service pages

Redirect or return 410 where appropriate.

Custom 404 page status

Confirm the 404 page returns a real 404 status.

Redirect examples

Good and bad redirect examples 
Good redirect:

Old URL:
https://example.com/services/web-hosting

New relevant URL:
https://example.com/hosting

Result:
301 → https://example.com/hosting
Final status: 200 OK

Bad redirect:

Old URL:
https://example.com/services/web-hosting

Redirect:
301 → https://example.com/

Problem:
The homepage is not the closest relevant replacement.

Correct approach:
Redirect to a relevant service/category page or restore the content.

No replacement:

Old URL:
https://example.com/old-event-2018

No relevant replacement exists.

Correct response:
404 or 410 may be acceptable.

Examples are illustrative. Redirect decisions should be based on content relevance, user intent, traffic and backlinks.

404 troubleshooting examples 
Example 1: Sitemap 404

URL:
https://example.com/old-guide

Status:
404

Problem:
URL is still listed in sitemap.

Fix:
Remove from sitemap, restore page or redirect to relevant replacement.

Example 2: Internal broken link

Page:
https://example.com/blog

Links to:
https://example.com/services/old-hosting

Status:
404

Fix:
Update internal link to the current hosting page.

Example 3: Backlink target missing

Backlink points to:
https://example.com/research-report

Status:
404

Fix:
Restore report or redirect to the closest current report/resource.

Examples are illustrative. Check real traffic, links and replacement relevance before redirecting.

Custom 404 page

A good 404 page helps users recover.

Include:

  • clear message that page was not found
  • link to homepage
  • search box if available
  • popular pages or categories
  • contact/support link
  • brand-consistent design
  • helpful tone
  • no confusing technical language
  • real 404 status code

Avoid:

  • returning 200 OK for a 404 page
  • automatically redirecting every missing URL to homepage
  • blaming the user
  • hiding navigation
  • showing a blank server error page

Soft 404s

A soft 404 happens when a page looks like a missing page but returns 200 OK instead of 404 or 410.

Examples:

  • “Page not found” content with 200 status
  • empty product page with 200 status
  • search page saying no results with indexed URL
  • deleted article template returning 200
  • irrelevant homepage redirect treated as not useful

Soft 404s can confuse search engines because the server says the page exists even though the content is missing.

Frequently asked questions

Are 404 errors bad for SEO?

Not always. 404s are normal for URLs that do not exist, but important 404s should be fixed.

How many 404s is too many?

There is no universal number. The impact depends on whether important URLs, internal links, sitemap URLs or backlinks return 404.

Should I redirect all 404s to the homepage?

No. Redirect only when there is a relevant replacement.

What is the difference between 404 and 410?

404 means not found. 410 means the page is intentionally gone.

Should deleted pages always be redirected?

No. If there is no relevant replacement, 404 or 410 can be correct.

What is a soft 404?

A soft 404 is a missing or empty page that returns 200 OK instead of a proper 404/410.

What should I fix first?

Fix sitemap 404s, internal broken links, high-traffic missing pages and URLs with backlinks first.

Use these free tools to verify your configuration after applying changes.

Website Status Checker HTTP Header Checker Domain Health Checker DNS Lookup SSL Checker
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