You click a link. It doesn’t work.
404 error: Page not found.
These errors usually happen because of something small, like a page that moved, a broken link, or an access rule that blocked the request. 4xx errors are common, but they have more of an effect on SEO and site performance than you might think.
How HTTP Errors Affect SEO and User Experience
Load errors are nothing dramatic on their own, but patterns matter. When an error happens once, it’s forgettable. When users run into errors or interruptions, many simply leave, and a bad first experience is often enough to keep them from returning. A click goes nowhere. The visit ends, and your CTR takes a hit.
Search engines don’t react emotionally, but they do react to patterns. Broken links waste crawl budget. Missing pages make the site structure hard to interpret. When errors repeat, important pages slowly lose ground.
Too many unresolved errors on your site could mean losing the first-page rankings you worked so hard to earn.
What Causes 4xx Client-Side Errors?
Most HTTP errors aren’t noticeable at first. A redesign goes live. A page name changes. Old content is archived. Internal links don’t always get updated at the same pace. Pages go missing, and visitors to your site see the dreaded “404 error: Page not found” message.
But that’s only one type of 4xx error.
Login requirements, file permissions, blocked IP addresses—even browser cache issues can cause 4xx errors. Access settings can trigger errors, too. And because every different trigger has a different solution, guessing at how to fix them will only make things worse.
All 4xx errors live in the same category, but they answer different questions about what happened and why a page didn’t load. Let’s go over each type of error, what it means, and how to fix it.
Common Types of HTTP Status Errors and How to Fix Them
Large-scale website studies have shown that broken links are surprisingly common, even on high-traffic sites. And unfortunately, client-side issues can go completely unnoticed unless you’re checking for errors on a regular basis.
404: Not Found
The page isn’t there. Or at least, it’s not there anymore.
- Common causes: Pages that were moved or deleted without redirects, broken internal links, incorrect or outdated URLs
- How to fix it: Add 301 redirects for moved pages, update broken links, restore missing content when appropriate, and use a simple custom 404 page
400: Bad Request
The request itself didn’t make sense to the server.
- Common causes: Corrupted cache or cookies, poorly formatted URLs, invalid form submissions
- How to fix it: Clear cache and cookies, check URL formatting, review form or request settings
401: Unauthorized
Access was required, but it didn’t work.
- Common causes: Invalid login credentials, expired sessions, misconfigured authentication settings
- How to fix it: Confirm credentials, reset authentication tokens, review access controls
403: Forbidden
The server understood the request. Access is still blocked.
- Common causes: Incorrect file permissions, blocked IP addresses, restrictive server rules
- How to fix it: Adjust permissions, review firewall or server rules and remove unnecessary restrictions
410: Gone
The page is gone, permanently.
- Common causes: Intentional content removal, outdated URLs still indexed
- How to fix it: Use a 410 only when content is truly gone, or redirect if a replacement exists
Choose the Website Experts at New Wine Digital for Your Website Design and Maintenance
As a business owner, you need to keep your websites accessible, optimized, and functional—without all the constant guesswork. If broken links, recurring errors, or maintenance tasks keep stacking up, let New Wine Digital handle them for you.
At New Wine Digital, we help businesses stay ahead of website errors before they start affecting performance or search visibility. These issues don’t always announce themselves, but they can impact usability, visibility, and trust over time. That’s why we focus on proactive website maintenance and monitoring, including:
- Routine website audits to catch broken links early
- Redirect management to prevent dead ends
- Monitoring error reports and site performance for patterns
- Maintaining clean, consistent URL structures
- Reviewing permissions and access controls to avoid accidental blocks
Photo by Erik Mclean on Unsplash used with permission under the Creative Commons license for commercial use 03/03/2026