2025 Guide to Broken URL Errors: 404, 500, and Other Common Codes Explained

Encountering broken URLs or error codes like 404 Not Found or 500 Internal Server Error can be frustrating for both website visitors and webmasters. Broken links lead to dead-end pages, leaving users with empty screens and poor experience. Understanding these error codes is crucial for maintaining a healthy, user-friendly website and improving your SEO.

What Is a Broken Link?

Broken links are hyperlinks that fail to direct users to the intended webpage. When clicked, these links often trigger error codes indicating that the requested page cannot be found or accessed. Common causes include:

• Deleted or moved content.
• Incorrect URL entries.
• Non-existent or expired domains.
• Website restructuring.
• Expired links from external sources.

The most recognizable broken link error is the 404 Not Found, but there are many other error codes that webmasters should understand.

Most Common Broken URL Error Codes and Their Meanings

Here is a comprehensive list of the most frequent broken URL error codes and their definitions:

• 400 – Bad Request: The server could not understand the request due to invalid syntax.
• 401 – Unauthorized: The requested resource requires authentication.
• 403 – Forbidden: The server understood the request but refuses to fulfill it.
• 404 – Not Found: The server cannot find the requested URL.
• 405 – Method Not Allowed: The HTTP method used is not allowed for the requested resource.
• 406 – Not Acceptable: The server cannot generate a response that matches the client’s accepted headers.
• 407 – Proxy Authentication Required: Similar to 401, but requires authentication with a proxy server.
• 408 – Request Timeout: The client did not send a request within the server’s waiting period.
• 409 – Conflict: The request could not be completed due to a conflict with the current resource state.
• 410 – Gone: The resource is permanently unavailable and no forwarding address exists.
• 411 – Length Required: The server refuses to accept the request without a defined Content-Length.
• 412 – Precondition Failed: A precondition in the request header evaluated to false on the server.
• 413 – Request Entity Too Large: The request entity exceeds the server’s processing capacity.
• 414 – Request-URI Too Long: The URL requested is longer than the server can handle.
• 415 – Unsupported Media Type: The request entity is in a format not supported by the resource.
• 416 – Requested Range Not Satisfiable: The requested range of data is outside the server’s available range.
• 417 – Expectation Failed: The server cannot meet the expectation specified in the request header.

Common Reasons for Broken Links

Broken links can arise from several issues, including:

• URL Structure Changes: Modifications in website hierarchy or permalinks can make old links invalid.
• Deleted Pages: Removing pages without proper redirection results in broken links.
• Relocation Without Redirects: Moving pages requires 301 redirects to preserve link integrity.
• Typographical Errors: Simple typos in URLs can prevent pages from loading.
• Poorly Implemented 301 Redirects: Incorrect redirects can lead to errors instead of the intended page.

How to Find Broken Links on Your Website

Regular monitoring of broken links is crucial for SEO and user experience. You can detect broken links using:

• Google Search Console: Provides detailed reports of 404 errors and broken URLs.
• Ahrefs or SEMrush: These SEO tools scan your website and generate broken link reports.
• Manual Log Checking: Reviewing server logs for 404 errors can help identify problematic URLs.

Proactively finding and fixing broken links ensures a seamless browsing experience for your visitors and prevents negative SEO impacts.

Conclusion

Understanding and managing broken URL error codes is vital for a well-maintained website. Whether it’s a simple 404 Not Found or a complex 500 Internal Server Error, knowing the meaning behind each code helps you quickly diagnose issues and implement fixes. Regular monitoring, correcting URL structures, and properly using redirects improve both user experience and SEO, ultimately boosting engagement and success for your website.