A 404 error is one of the most common HTTP status codes you will encounter when managing a website. It appears when a browser or search engine requests a URL, but the server cannot find the requested resource.

For visitors, this usually means seeing a message such as “404 Page Not Found”. For website owners and SEO professionals, however, a 404 can indicate anything from a harmless deleted page to a broken internal linking structure that wastes traffic, backlinks and crawling resources.

This 404 explanation covers what the status code means, why 404 errors occur, their impact on SEO and how to decide whether a missing URL should be restored, redirected or deliberately left as a 404.

What Is a 404 Error?

A 404 error is an HTTP response status code indicating that the server could be reached but could not find the requested page or resource.

In simple terms:

Browser requests URL → Server receives request → Resource cannot be found → Server returns HTTP 404

For example, imagine your website previously contained:

example.com/seo-guide/

If that page is deleted without a redirect and someone visits the old URL, the server may respond with:

HTTP/1.1 404 Not Found

The important distinction is that a 404 does not normally mean the entire website or server is unavailable. The server is responding; it simply cannot locate the particular resource requested.

What Does 404 Not Found Mean?

The 404 Not Found status belongs to the 4xx family of HTTP response codes. These codes generally indicate that the request cannot be fulfilled because of an issue associated with the requested resource or client request.

The number itself can be understood within the wider HTTP status code structure:

• 2xx: Successful requests
• 3xx: Redirection
• 4xx: Client-side/request-related errors
• 5xx: Server-side errors

A 200 OK tells a browser or crawler that the requested content exists.

A 301 Moved Permanently indicates that the resource has permanently moved elsewhere.

A 404 Not Found indicates that the server cannot find the requested resource.

Understanding these distinctions matters in technical SEO because search engines treat each response differently.

What Causes 404 Errors?

A 404 error can occur for several reasons. Some are completely normal, while others indicate problems that should be investigated.

A Page Has Been Deleted

Deleting a page is probably the most obvious cause.

Suppose an ecommerce website removes an old product and its URL disappears. Anyone following an old bookmark, search result or backlink to that product may encounter a 404.

Deleting a page is not inherently bad for SEO. The important question is whether the deleted URL still has value.

If it has backlinks, organic traffic or a suitable replacement, simply removing it may not be the best option.

The URL Has Changed

Changing a URL without implementing a redirect creates another common source of 404 errors.

For example:

example.com/seo-audit-guide/

might be changed to:

example.com/technical-seo-audit/

If the old URL is removed without a 301 redirect, links pointing to it will lead visitors and search engines to a 404 page.

This is particularly important during website redesigns and migrations, where hundreds or thousands of URLs may change simultaneously.

Internal Links Contain Mistakes

Sometimes the page exists, but the hyperlink pointing towards it is incorrect.

For example:

Correct URL:

example.com/link-building/

Incorrect internal link:

example.com/link-buidling/

That small spelling error can generate a 404.

Broken internal links are worth fixing because they affect both user navigation and search engine crawling.

External Websites Link to the Wrong URL

Not every 404 originates from your own website.

Another publisher might link to:

example.com/seo-tools

when the actual page is:

example.com/seo-tools/

Server configuration can determine whether such variations resolve correctly.

More significant spelling mistakes or incorrect paths can result in external backlinks pointing directly to nonexistent pages.

For link-building campaigns, checking these broken backlink destinations can occasionally uncover easy opportunities to recover link equity.

Website Migration Problems

Site migrations are a major source of widespread 404 errors.

Problems can appear when moving:

• HTTP to HTTPS
• one domain to another
• one CMS to another
• subdomains into folders
• old URL structures into new structures

If old URLs are not mapped properly to their new equivalents, previously indexed pages and backlinks may suddenly lead to 404 responses.

A proper redirect map should therefore be prepared before a major migration rather than after traffic starts falling.

Are 404 Errors Bad for SEO?

A few genuine 404 pages are not automatically an SEO problem.

Websites naturally change. Products disappear, outdated content gets removed, and old URLs eventually become irrelevant. Search engines expect this.

The SEO problem begins when 404 errors affect valuable URLs or appear because of poor website maintenance.

When a 404 Can Hurt SEO Performance

You should pay particular attention when a 404 URL:

• has valuable external backlinks
• previously generated organic traffic
• remains linked from important internal pages
• should have been redirected during a migration
• has a clear replacement page
• is appearing because of broken navigation
• represents an accidentally deleted page

Consider a page that has earned backlinks from 30 relevant websites.

If that URL is accidentally deleted, visitors following those links encounter an error, and the SEO value associated with the old page may no longer contribute as effectively to the intended destination.

A well-matched 301 redirect could preserve much more of that value.

When Leaving a 404 Is Correct

Not every missing page needs redirecting.

If a page has been deliberately removed, has no meaningful backlinks or traffic, and there is no genuinely relevant replacement, returning a proper 404 can be perfectly reasonable.

This is better than redirecting every deleted URL to the homepage.

Search engines and users benefit from clear signals. A completely irrelevant redirect does not suddenly make a deleted resource useful.

404 vs 301 Redirect: Which Should You Use?

The right response depends on what happened to the content.

Situation	Recommended Action
Page moved permanently	301 redirect
URL changed but content remains	301 redirect
Old page has a highly relevant replacement	Usually 301 redirect
Page deleted permanently with no replacement	404 or 410
URL never existed	404
Broken internal link caused by typo	Correct the internal link
Valuable page deleted accidentally	Restore it or redirect appropriately

The core rule is relevance.

If Page A has moved to Page B, a 301 makes sense.

If Page A was about technical SEO and Page B sells unrelated clothing, redirecting one to the other simply to eliminate a 404 does not.

404 vs 410

A 404 Not Found means the requested resource cannot be found.

A 410 Gone provides a stronger indication that the resource has deliberately and permanently been removed.

Both can be legitimate. For most routine website maintenance, a correctly configured 404 is sufficient. A 410 may be useful where you deliberately want to communicate that a resource has permanently disappeared.

What Is a Soft 404?

A soft 404 occurs when a page appears to be missing or effectively useless, but the server returns a successful response such as 200 OK rather than a proper 404 status.

For example, a website might display:

Sorry, this product no longer exists.

But technically return:

200 OK

That sends conflicting signals.

The visitor sees a missing page, while the server tells search engines that a valid resource exists.

Search engines may identify these pages independently and classify them as soft 404s.

From an SEO perspective, it is generally better to return an accurate HTTP response rather than relying solely on the visible message shown to visitors.

How to Find 404 Errors on Your Website

Finding 404s requires more than manually clicking around your website.

Several SEO tools can identify broken URLs efficiently.

Google Search Console

Google Search Console can reveal URLs Google has attempted to crawl but could not find.

Check indexing reports for Not found (404) URLs.

Do not assume every URL listed needs fixing. Review why the URL exists and whether Google discovered it through an internal link, sitemap, old page or external source.

Prioritise URLs that previously held SEO value.

Screaming Frog SEO Spider

Screaming Frog is particularly useful for finding broken internal links.

Crawl your website and filter responses by Client Error (4xx). You can then inspect which internal pages link to each broken destination.

This makes it easier to correct the source rather than merely identifying the error.

Ahrefs and Semrush

Backlink and site-audit platforms such as Ahrefs and Semrush can help identify broken pages and, importantly, missing URLs that still have backlinks.

That distinction matters for link building.

A 404 page with zero backlinks may be low priority. A 404 page with several strong editorial links could represent recoverable authority.

How to Fix 404 Errors Properly

There is no single fix for every 404. The correct solution depends on why the URL is missing.

1. Restore Accidentally Deleted Content

If an important page disappeared by mistake, restoring the original URL can be the cleanest solution.

This is particularly useful when the page already ranks, receives backlinks or generates traffic.

2. Add a 301 Redirect When Content Has Moved

If the content has a new permanent location, redirect the old URL to its closest equivalent.

For example:

/old-seo-guide/ → /seo-guide/

This provides users with a logical destination while telling search engines that the resource has permanently moved.

3. Repair Broken Internal Links

If your own website links to an incorrect URL, fix the hyperlink directly.

Do not rely exclusively on redirects to compensate for poor internal linking.

Clean internal links reduce unnecessary redirect hops and make crawling more efficient.

4. Recover Broken Backlinks

Broken backlinks deserve special attention in SEO and link-building campaigns.

Imagine an old guide has acquired links from reputable industry publications but now returns a 404.

You could:

• restore the original content;
• create an improved replacement at the same URL; or
• redirect the URL to a closely related resource.

This can be a relatively efficient way of recovering authority that the website has already earned.

5. Leave Legitimate 404s Alone

Sometimes the right fix is no fix at all.

If an irrelevant URL never existed, has no internal links, carries no useful backlinks and receives no meaningful traffic, there may be little reason to redirect it.

Technical SEO should prioritise impact rather than chasing a perfect zero-error report.

Why Custom 404 Pages Still Matter

The HTTP response and the visible 404 page serve different purposes.

The server response communicates with browsers and search engines. The custom 404 page helps the human visitor recover from the dead end.

A useful 404 page should include:

• clear confirmation that the requested page cannot be found;
• a link back to the homepage;
• navigation to important sections;
• a search function where appropriate;
• helpful links to popular resources.

Avoid making the page overly complicated.

Its job is not to rank for keywords. Its job is to help a visitor who has reached the wrong URL find somewhere useful to go next.

404 Errors in SEO, Guest Posting and Link Building

404 monitoring becomes particularly useful when evaluating backlinks.

Suppose an SEO agency is analysing a prospect’s backlink profile and discovers that several high-quality publications point to dead pages. Those links already exist. The opportunity is therefore different from traditional outreach.

Rather than immediately building more links, it may make sense to recover the value of existing links first.

The same principle applies after guest posting campaigns. If you later restructure your website, URLs used as destinations in previously published guest posts should be preserved or redirected appropriately.

Otherwise, links you paid for or earned through outreach may eventually point to dead pages.

For websites investing heavily in guest posting and link building, periodic broken backlink checks should therefore form part of routine SEO maintenance.

How 404 Problems Typically Grow Over Time

Think of 404 accumulation as a simple trend line.

A small website may begin with 5–10 harmless missing URLs.

After content pruning and product removals, that might increase to 50–100 URLs.

Following an unmanaged migration, the number could jump into the hundreds or thousands.

The number itself is not the most useful SEO metric.

A website with 1,000 harmless 404s may have less of a problem than a website with five 404 URLs that collectively hold hundreds of valuable backlinks.

The more useful correlation is:

SEO importance of 404 = URL value × quality of links × traffic potential × internal importance

Prioritisation should therefore be based on value, not simply error count.

A Practical 404 Audit Workflow

When auditing 404 errors, use a structured process:

1. Crawl the website for broken internal URLs.
2. Review 404 reports in Google Search Console.
3. Export broken pages from your backlink analysis tool.
4. Identify URLs with traffic, rankings or backlinks.
5. Determine whether each page was moved, deleted or entered incorrectly.
6. Restore important accidentally deleted pages.
7. Redirect moved pages to genuinely relevant replacements.
8. Correct internal links at their source.
9. Leave legitimate low-value missing URLs as 404s.
10. Re-crawl the website to confirm the fixes.

This approach prevents the common mistake of applying blanket redirects simply to make an SEO audit appear cleaner.

Frequently Asked Questions About 404 Errors

What does error 404 mean?

A 404 error means the server cannot find the page or resource requested by the visitor or search engine. The website itself may still be working normally; only the requested URL is unavailable.

Does a 404 error hurt SEO?

A normal 404 does not automatically harm SEO. Problems arise when important pages, internal links, backlinks or URLs that should have been redirected return 404 errors.

Should I redirect every 404 page?

No. Redirect a 404 when there is a genuinely relevant replacement or the content has moved. Irrelevant redirects, particularly sending every missing URL to the homepage, are not good technical SEO practice.

What is the difference between 404 and 301?

A 404 indicates that a resource cannot be found, while a 301 indicates that a resource has permanently moved to another URL.

How do I find 404 pages?

You can identify 404 pages using Google Search Console, website crawlers such as Screaming Frog, server logs and SEO platforms including Ahrefs and Semrush.

What is a soft 404?

A soft 404 is a page that appears to users or search engines as missing or effectively empty but returns a successful HTTP response, often 200 OK, rather than an appropriate 404 response.

The Right Way to Handle 404 Errors

A good 404 explanation ultimately comes down to understanding intent: the server is telling you that a requested resource cannot be found, but that does not automatically mean something is technically wrong with the website.

For SEO, focus on valuable 404s rather than every 404.

Restore important content when it was removed accidentally; use 301 redirects when resources genuinely move; repair broken internal links; and investigate dead URLs that still receive authoritative backlinks. At the same time, allow genuinely deleted and irrelevant URLs to return a proper 404 when there is no useful replacement.

That combination creates cleaner crawling signals, protects valuable backlinks and provides a better experience for visitors without resorting to unnecessary redirects.