What Is a 404 Not Found Error? Causes and Detailed, Fast Solutions

The 404 Not Found error is one of the most common HTTP status codes that Internet users encounter, appearing when the server cannot find the requested page or resource. In this article, Vcloudia will help you understand the causes, impacts, and effective troubleshooting methods for both users and website administrators.

What Is a 404 Not Found Error?

The 404 Not Found error (also known as a query error when the browser communicates with the server) is a standard HTTP response code indicating that the web server cannot locate the page or resource requested by the user. When a browser sends a request to a URL where the server has no corresponding content, a 404 error message is returned so that the user knows the visited address does not exist on the system.

Common variations of 404 notifications include:

- 404 Error

- Error 404

- 404 Not Found

- Error 404 Not Found

- HTTP 404

- 404 File or Directory Not Found

- 404 Page Not Found

- The requested URL was not found on this server

Causes of 404 Not Found Errors

A 404 Not Found error can originate from both the user side and the server or website side. Some common causes include:

- Mistyped URL: When users mistype a URL, miss characters, or use incorrect syntax, the browser cannot find the intended web page, resulting in a 404 error.

- Changed or Deleted URL: Restructuring a website, renaming, moving, or deleting pages without configuring appropriate redirects invalidates old links; accessing the old URL will return a 404 error message.

- Corrupted Browser Cache or Cookies: If cache or cookies store an outdated version of a website where data has been deleted or updated, a 404 error may appear when reloading the page.

- Technical Issues from the Website: Server misconfigurations, code errors, redirect errors, or conflicting plugins and extensions affecting data sources can cause the website to return a 404 error when resources cannot be found.

- DNS or Server Connection Issues: Issues with DNS servers, DNS blocking, or unstable network connections are also among the causes of 404 Not Found errors.

- Unintended Database Changes: Modifications, updates, or removals of related data can generate broken links, leading to errors when users access them.

Impacts of 404 Not Found Errors

404 Not Found errors cause many negative impacts on website operations as well as user experience. When frequently encountering 404 errors, users experience interrupted workflows, frustration, and a loss of trust in the website's quality. This situation may drive visitors to leave the page or switch to competitors' services, causing businesses to lose potential customers.

Additionally, 404 errors negatively affect SEO and business performance. Search engines downgrade websites with numerous broken links, leading to lower keyword rankings and a noticeable drop in organic traffic. For e-commerce or service-oriented websites, frequent 404 errors can disrupt the purchasing process, reduce revenue, and degrade digital brand equity.

Free 404 Not Found error checker tool

Google Search Console

Google Search Console is a free tool from Google that helps website administrators monitor, detect, and control 404 Not Found error URLs on their websites. The Coverage feature provides detailed reports on problematic pages, assisting in the timely identification and resolution of non-existent links while assessing the error's impact on website SEO performance. Users can access the Pages or Crawl sections to look up error-affected URLs and implement appropriate adjustments.

Screaming Frog SEO Spider

Screaming Frog SEO Spider is software that enables crawling entire websites to detect links returning the 404 Not Found status code. The free version supports checking up to 500 URLs, allowing small and medium website administrators to easily spot errors and export reports. This tool integrates multiple advanced SEO analysis features to support effective website optimization.

Xenu Link Sleuth

Xenu Link Sleuth is a useful free tool for crawling and checking all existing links on a website. Xenu works by discovering and cataloging all links, then providing detailed reports on 404 error links along with their locations so administrators can easily fix them. This tool is well-suited for periodic audits to help websites optimize user experience and mitigate SEO penalties.

Broken Link Checker

Broken Link Checker is an online tool that allows checking for broken links, including 404 errors, on a website without installing software. Users simply paste the URL into the system, and the tool will automatically crawl and display a list of broken links, supporting the rapid resolution of broken pages that impact SEO.

How to effectively fix the 404 Not Found error

Reload the Webpage

Sometimes a 404 Not Found error occurs due to temporary connection or data transfer issues on the server or browser side. Users can press the reload button (F5) in the browser to request the web page content again. This process helps determine whether the error is merely a temporary issue.

Clear Browser Cache and Cookies

When the browser caches outdated versions of web pages or stores obsolete cookies, users may encounter a 404 error if those pages have been modified or deleted on the server. Clearing cache and cookies ensures the browser fetches the latest version from the server, eliminating the risk of errors caused by stale data.

Check and Correct the URL

Entering an incorrect URL is a common cause of 404 Not Found errors. Users should carefully review every character in the URL to ensure there are no missing, extra, or misspelled characters. If an incorrect link is identified, correcting it and attempting to access it again will quickly eliminate this error.

Search for and Update the New URL

When a website changes its structure or migrates content, old URLs may no longer exist. Users should search for or contact administrators to obtain the new address details. Using the correct URL ensures access to the desired content without encountering a 404 error.

Change DNS Servers

DNS errors can also prevent web pages from being accessed and lead to a 404 Not Found error. Users can try switching to alternative DNS servers (such as Google DNS or OpenDNS) to test and rule out this cause. This action helps determine whether the error stems from network issues or the service provider.

Set Up 301/302 Redirects

Website owners should set up redirects from old URLs returning 404 errors to relevant content pages or the homepage. This keeps users on the website while preserving search rankings and SEO equity for modified legacy addresses.

Use 404 Error Checking Tools

Website administrators should regularly use auditing tools like Google Search Console, Screaming Frog, or Broken Link Checker to review and detect broken links. These tools support early detection, export specific reports, and provide bulk-handling solutions for 404 errors across the website.

Contact Technical Specialists or Website Administrators

If all the above methods have been attempted and the 404 Not Found error persists, users or website owners should contact technical specialists, the development team, or the service provider for guidance and definitive resolution. This is particularly vital for large websites or online business operations.

Frequently Asked Questions

How do I create a custom 404 page for a website?

Most content management systems like WordPress allow you to easily create a custom 404 Not Found page through plugins or theme settings. For beginners, understanding what 404 is or what an HTTP 404 error means is crucial; it is a notification indicating that the page you requested does not exist or has been moved. A user-friendly 404 error page should feature a clear message, a search bar, and helpful links to retain users and reduce bounce rates.

Is a 301 redirect the best way to handle broken links?

The answer is yes. When facing a 404 Not Found error, a 301 redirect is the most recommended method because it informs both users and search engines that the page has permanently moved to a new address. This method not only resolves the 404 Not Found error effectively but also preserves SEO link equity from the old URL to the new one, significantly improving user experience.

Should 404 pages be blocked in the robots.txt file?

The answer is no. You should not block 404 Not Found pages in the robots.txt file. Doing so prevents Google from crawling and recognizing that those pages no longer exist, causing them to potentially linger in search results and degrade user experience. Allow Google to freely crawl these 404 error pages and remove them naturally from the index; this is the most organic and effective way to resolve 404 Not Found errors for a website.

Conclusion

The 404 Not Found error is an inevitable issue during website operation. For users, understanding the underlying causes helps resolve access issues quickly. For website administrators, proactively utilizing tools to detect and implement fixes such as 301 redirects is key to maintaining a good user experience, protecting SEO rankings, and ensuring online business performance.