What is HTTP 404 Not Found?

What does it mean in practice?

For web applications, HTTP 404 Not Found can affect performance, compatibility, caching, data storage and migration planning.

What does an HTTP 404 response tell you?

An HTTP 404 response confirms that the web server answered the request, but the requested URL does not currently resolve to a page, file or application route. The server itself can still be online and other addresses on the same website may work normally.

This page is an educational Hostilla.pl glossary article about the HTTP status. It is not an error response: the article itself returns HTTP 200 and explains how to diagnose a real 404 on a website.

Common causes of HTTP 404

• a mistyped or outdated URL
• a page or file that was moved or deleted
• an incorrect document root after a hosting migration
• missing rewrite rules or an incomplete .htaccess file
• broken CMS permalinks or application routes
• a stale internal link, menu item, sitemap entry or cached address

How to troubleshoot a 404 on your website

1. Open the exact URL in a private browser window and check for typing or letter-case differences.
2. Confirm that the expected file, page or route exists in the correct domain directory.
3. Check the domain document root, rewrite rules, CMS permalink settings and recent deployments.
4. Review server and application logs for the requested path and test time.
5. Update broken internal links and the XML sitemap, then clear website, proxy and browser caches.

HTTP 404, soft 404, HTTP 410 and redirects

A genuine missing resource should return HTTP 404. A soft 404 is a page that returns HTTP 200 but looks like an empty or missing-page message to users or search engines. HTTP 410 explicitly says that a resource was removed permanently. If useful content moved to a clear replacement URL, a permanent redirect is usually better than leaving visitors at a dead address.

Should every 404 be redirected?

No. Redirect only when there is a relevant replacement. Redirecting every missing address to the homepage can confuse visitors and search engines. Fix important broken links, keep a useful custom 404 page for genuinely unknown URLs and remove obsolete addresses from navigation and sitemaps.