404 errors in GSC – Crawl Stats and uncontrolled Dynamic URL Generation

Causes and Solutions for „Uncontrolled Dynamic URL Generation” -Understanding Issue

If you’re seeing numerous 404 errors in Google Search Console (GSC) under Settings > Crawl Stats > Crawl Requests, with URLs that look like randomly generated strings (e.g., /26123wmqv50356889hv597d8ccf), your WordPress site may be facing an Uncontrolled Dynamic URL Generation issue.

Common Causes of Uncontrolled Dynamic URL Generation

1. Plugin or Theme Bugs: Some WordPress themes or plugins may generate incorrect dynamic URLs due to improper coding or unintended interactions.
2. Invalid URL Parameters: Poorly validated query parameters can lead to incorrect or non-existent URLs being crawled by search engines.
3. Automated Bot Activity: Malicious or spam bots may attempt to access non-existent pages, resulting in a flood of 404 errors.
4. Incorrect Internal Linking: A misconfiguration in page navigation or filtering can create links to pages that don’t exist.
5. CMS Issues: Some WordPress settings or third-party tools may generate unnecessary query strings or dynamic paths that do not lead to valid content.

Fixing this issue is crucial to prevent excessive 404 errors, which can harm your SEO and crawl budget.

Steps to Fix Uncontrolled Dynamic URL Generation in WordPress

1. Identify the Source of the Problem

Start by checking which parts of your site generate these invalid URLs:

• Review your Google Search Console > Settings > Crawl Stats > Crawl Requests for 404 errors.
• Check the Indexing Status in GSC to find patterns in URL errors.
• Examine plugins or custom scripts that might be generating these URLs.

2. Implement URL Parameter Validation in functions.php

To prevent unwanted parameters from being processed, add a validation function in your WordPress theme’s functions.php file.

How to Add URL Validation in functions.php

1. Open your WordPress admin panel.
2. Navigate to Appearance > Theme File Editor.
3. Select functions.php from the right sidebar.
4. Add the following code at the end of the file:

add_action('template_redirect', 'validate_url_parameters');

function validate_url_parameters() {
    // Allowed parameters (modify as needed)
    $allowed_params = array('id', 'page', 'category');

    // Loop through all URL parameters
    foreach ($_GET as $param => $value) {
        // Block unexpected parameters
        if (!in_array($param, $allowed_params)) {
            wp_die('Invalid URL parameter: ' . esc_html($param), '404 Not Found', array('response' => 404));
        }

        // Validate parameter values (only letters, numbers, underscores, or hyphens)
        if (!preg_match('/^[a-zA-Z0-9_-]+$/', $value)) {
            wp_die('Invalid value for parameter: ' . esc_html($param), '404 Not Found', array('response' => 404));
        }
    }
}

3. Block Unwanted URLs in Robots.txt

Another way to prevent Google from crawling invalid dynamic URLs is by blocking them in your robots.txt file.

How to Edit Your Robots.txt File

1. Access your site via FTP or use an SEO plugin like Yoast SEO to edit robots.txt.
2. Add the following rule:

User-agent: *
Disallow: /*?

This prevents search engines from indexing any URL with a ? parameter, which is useful if your site doesn’t rely on query strings for navigation.

4. Use Redirects for Commonly Accessed 404 URLs

If Google has already indexed these invalid URLs, set up 301 redirects for them.

How to Set Up Redirects in WordPress

• Use a plugin like Redirection.
• Go to Tools > Redirection and add redirects from the invalid URLs to a relevant page.

5. Monitor and Optimize

After implementing the fixes, continue monitoring Google Search Console for:

• A reduction in 404 errors.
• Fewer dynamically generated URLs.
• Improved crawl efficiency.

Conclusion

The Uncontrolled Dynamic URL Generation issue can negatively impact your SEO by generating unnecessary 404 errors. By validating URL parameters, blocking unwanted URLs in robots.txt, and setting up redirects, you can significantly improve your site’s performance and crawl efficiency.

Following these steps will help prevent future issues and maintain a clean URL structure for better SEO results.

For SEO experts seeking to master these advanced features, enrolling in our Google search console course is the perfect next step.