What is a 404 error and how to fix it

Every time a visitor follows a link on your site and lands on a page that no longer exists, they see a 404 error. You may never notice it happened. They already left. 404 errors are one of the most common problems on sites that have been running for a while, and they build up quietly while your analytics show no obvious cause for why visitors keep bouncing before they ever read a word.

A single broken destination is not catastrophic on its own. But 404 errors tend to multiply over time. Pages get deleted, URLs change, links stop pointing to the right place. None of it announces itself. Understanding why website maintenance matters starts with recognizing that errors like these do not fix themselves. Left unaddressed, they chip away at user experience and search performance at the same time.

This article covers what a 404 error is, the common reasons they appear, how they affect your site, how to find them, and the steps to fix them.

What is a 404 error?

A 404 error is an HTTP status code that a web server returns when the page a visitor requested does not exist at that URL. The browser made the request, the server understood it, and the server responded with a clear answer: that page is not here.

The number 404 is part of the HTTP response code system. Codes in the 400 range indicate a client-side problem, meaning the issue is with the request rather than the server. A 404 specifically means the resource was not found. It is different from a 500 error, which signals a server problem, or a 301, which is a redirect telling the browser to go somewhere else. When a visitor sees a 404, the server is working correctly. The page just does not exist at the address they requested.

Why do 404 errors happen?

404 errors appear for a handful of consistent reasons. Identifying the root cause makes it easier to choose the right fix.

Pages get deleted

When a page is removed from a site without any redirect in place, every link that pointed to that page now leads to a 404. This is the most common source of 404 errors on established sites. Old blog posts get pruned, product pages get removed, and services get discontinued. Each deletion creates a dead end unless the old URL is redirected to a relevant page.

URLs change

Changing a page's URL, whether by reorganizing the site structure, changing a slug, or moving content to a new section, breaks every link that referenced the old URL. The page still exists, but the address changed without the server being told to forward traffic from the old one.

Typos in links

A single incorrect character in a link creates a 404. This happens in manually written links inside blog posts, navigation menus, or external links pointing back to your site. The URL pattern looks right at a glance, but one misplaced letter or missing hyphen sends visitors to a page that cannot be found.

External links point to pages that no longer exist

Other websites link to your content. When those pages get deleted or moved without a redirect, the inbound link becomes a dead end for visitors following it from outside your site. You cannot control what other sites link to, but you can control what happens when someone arrives at a URL that no longer exists.

How do 404 errors affect your site?

Visitors leave

A visitor who lands on a 404 page hit a wall. There is no content to read, no path to follow, no reason to stay. If the error page does not give them a clear way back into the site, they leave. That visit is over, and the chance of converting them is gone. On pages that were receiving a meaningful amount of traffic, every unfixed 404 represents visits that end without a result.

Search engine impact

Search engines follow links just like visitors do. When a crawler follows a link and encounters a 404, it treats that page as removed from the site. If a page had accumulated backlinks or was indexed with ranking positions, those signals diminish over time once the page stops returning content. Internal 404 errors also interrupt how crawlers move through the site, meaning some pages may be found less frequently or not crawled at all.

Setting up what website monitoring is and why you need it is one way to catch these errors before they accumulate, rather than discovering them after they have been compounding for months.

How to find 404 errors on your site

Analytics data

Web analytics platforms log every page viewed on your site, including 404 pages. If your 404 template fires a page view with a consistent title or path pattern, you can filter your analytics reports to find which URLs are returning errors and how much traffic they are receiving. This tells you which 404 errors are actively costing you visits right now, so you can prioritize the fixes with the most impact first.

Crawl the full site

A site crawl follows every internal link on your site and records the HTTP status code each URL returns. This catches 404 errors that analytics might miss, including broken links on low-traffic pages, broken navigation items, and internal links buried in older content. Running a crawl periodically is part of how to update your website content regularly, because content changes frequently introduce new broken paths that only a crawl will catch comprehensively.

Check broken links

Dedicated link-checking tools scan every link on every page, including links to external sites, and report which ones return error codes. This is especially useful for catching 404 errors caused by outbound links to pages on other sites that have since been deleted or moved. Understanding what broken links are and why they hurt your site will help you prioritize which categories of broken links to address first and how each type affects visitors differently.

How to fix 404 errors

Set up a 301 redirect

A 301 redirect tells both browsers and search engines that a URL has permanently moved to a new address. When someone requests the old URL, the server sends them to the new one automatically. This is the right fix when a page was deleted or moved but similar content exists at a different URL. The redirect preserves any ranking signals the old URL had built up, because search engines transfer most of that value to the destination URL.

Restore the page

If a page was deleted by accident, or if the content it contained is still relevant and was generating traffic, restoring it at its original URL is often the cleanest option. Check your analytics to see how much traffic the URL was receiving before it was removed, and check whether inbound links from other sites were pointing to it. If both are true, restoring the page protects that traffic and those link signals.

Update or remove the link

When the 404 is caused by an internal link pointing to the wrong URL, fix the link directly. Update it to point to the correct address, or remove it entirely if the destination page no longer exists and no equivalent exists to redirect to. This applies to links in blog posts, navigation menus, footers, and anywhere else links are written manually. After updating a link, verify it by following it in a browser to confirm the destination loads correctly.

What a good 404 error page should do

Not every 404 can be anticipated with a redirect in place before it happens. A well-designed 404 error page reduces the damage when a visitor does land on one. The page should acknowledge clearly that the content they were looking for is not available at this address, without using technical language or error codes that mean nothing to a non-technical visitor.

From that acknowledgment, the page should give the visitor somewhere useful to go. A link to the homepage, a search box, and links to popular sections of the site all give a stranded visitor a path back into the content. A 404 page that simply displays an error message with no navigation sends every visitor who lands on it straight out the back door.

How WEMASY handles 404 errors

WEMASY's website builder includes a redirect manager that lets you set up 301 redirects from the dashboard without editing server configuration files. When a page is deleted or a URL changes, you can immediately add a redirect to send traffic to the correct destination. The platform also includes a customizable 404 error page so visitors who do land on a missing page see your branding, a clear message, and navigation links rather than a generic server error.

See what is included at the WEMASY website builder or review plans on the pricing page.

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