A 404 error is the web's way of saying "this page doesn't exist." When someone visits a URL on your site that doesn't have a corresponding page — whether because the page was deleted, renamed, or the URL was mistyped — your server returns a 404 status code, and the visitor sees an error page instead of your content.
What causes 404 errors
404 errors happen for several reasons, and not all of them are problems:
- Deleted pages: You removed a page but didn't redirect its old URL to a new one
- Renamed pages: You changed a page's URL slug and the old URL now leads nowhere
- Typos in links: Someone linked to your site with a misspelled URL
- Random URL guessing: Bots and crawlers try URLs that never existed (like /admin, /wp-login.php). These are normal and not your fault
- Site restructuring: You reorganized your site and URLs changed
When 404s hurt your SEO
Google's official position is that 404 errors by themselves don't hurt your rankings. A few 404s are normal and expected on any website. However, there are situations where 404s become an SEO problem:
When other sites link to 404 pages. If a blog, directory, or news site links to a page on your site that returns a 404, you're wasting that backlink. Backlinks are one of the strongest ranking signals in SEO, and every 404 page with external links pointing to it is a missed opportunity. Set up a redirect.
When internal links point to 404 pages. Broken internal links waste "link equity" — the SEO value that flows through your site's link structure. They also create a poor user experience that can increase your bounce rate.
When important pages return 404. If your services page, contact page, or any page that was previously ranking suddenly returns a 404, you'll lose that ranking immediately. Always redirect before deleting a page that gets traffic.
When 404s are fine
Not every 404 needs fixing:
- Random bot requests for URLs that never existed on your site (like /wp-admin on a non-WordPress site). These are normal and harmless
- Intentionally removed content that has no replacement and no external links. If a page was temporary and nobody links to it, a 404 is the correct response
- Misspelled URLs from user typos. You can't prevent people from mistyping URLs
Creating a custom 404 page
The default 404 page on most hosting providers is an ugly, unhelpful error message. A custom 404 page can turn a dead end into a navigation opportunity:
- Include your branding. Use the same header, footer, and design as the rest of your site so visitors know they're still on your website
- Explain what happened. A simple "This page doesn't exist" is better than a cryptic error code
- Provide navigation. Link to your homepage, popular pages, or a search bar. Give visitors a way to find what they were looking for
- Keep the tone friendly. "We couldn't find that page, but here are some places to start" is better than "Error 404"
How to set one up
WordPress: Create a file called 404.php in your theme folder. Most themes already include one — edit it to match your branding.
Squarespace / Wix: Both have built-in settings for custom 404 pages under page settings or site design.
Static sites / Apache: Create a custom 404.html page and add ErrorDocument 404 /404.html to your .htaccess file.
Monitoring 404 errors
The best approach is proactive monitoring rather than waiting for complaints:
- Google Search Console reports pages it tried to crawl that returned 404
- Server logs record every 404 response (check with your hosting provider)
- Regular broken link scans catch 404s from internal links. Run one monthly at minimum
Fix the ones that matter. Not every 404 needs attention, but the ones caused by broken links and deleted pages should be redirected. Run an Antileak scan to see which pages on your site return 404 errors and which ones have links pointing to them. Fix the high-impact ones first and your health score will improve.