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Why Broken Link Checker Shows False 404 Errors and How to Fix Them

47 threads Sep 9, 2025 Plugin → Broken link checker

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If you've ever received a notification from the Broken Link Checker plugin about a 404 error, only to find the link works perfectly in your browser, you're not alone. This is a common and often confusing issue reported by many users. This guide will explain why it happens and walk you through the most effective troubleshooting steps.

Why Does This Happen?

The core function of Broken Link Checker is to simulate a web request to each link on your site and interpret the response. A "404 Not Found" error in the plugin's report doesn't always mean a real visitor would see the same error. The discrepancy can occur for several reasons:

  • Complex Redirects: Some links, particularly affiliate or tracking URLs (like those from AliExpress), go through multiple redirects before landing on the final page. The plugin's checking engine might interpret one of these interim steps as a final 404 error, even though the ultimate destination is valid.
  • Server or Firewall Blocks: The target website might be blocking automated connection attempts from the plugin, interpreting them as a potential security threat. This can result in a "503 Service Unavailable," "Server not found," or a generic "Unknown Error" instead of a successful connection.
  • Local 404s: For links pointing to your own site, the plugin might receive a "200 OK" status from your server (meaning the page loaded) even if the content is a 404 error page. This depends on how your server and theme are configured.
  • Cached Data: The plugin might be checking a cached version of your site or its own cached results, showing outdated information.

How to Troubleshoot and Fix False 404 Reports

Follow these steps to identify and resolve the issue.

Step 1: Manually Verify the Link

First, double-check the reported link yourself. Open a new incognito or private browser window and paste the URL directly into the address bar. Observe what happens. If the link works fine, you are likely dealing with a false positive.

Step 2: Force a Recheck and Clear Cache

Before diving into complex solutions, try a simple reset. Navigate to WordPress Dashboard > Settings > Link Checker > Advanced. Click the "Forced recheck" button. This will clear the plugin's cache and rescan all links from scratch, which often resolves temporary glitches.

Step 3: Adjust Link Checker Settings (For Redirects)

If the problematic links involve complex redirects, you may need to adjust how the plugin handles them. Go to Settings > Link Checker > Which Links To Check. Ensure that the option to check redirected links is enabled. You can also try adjusting the "Timeout" and "Check link status" settings to be more lenient.

Step 4: Check for Conflicts

A theme or plugin conflict can sometimes interfere with the link checking process. To test for this:

  1. Temporarily switch to a default WordPress theme like Twenty Twenty-Four.
  2. Deactivate all other plugins except for Broken Link Checker.
  3. Run another forced recheck on the specific links.
  4. If the problem disappears, reactivate your themes and plugins one by one, checking after each, to identify the culprit.

Step 5: Review Server and Firewall Logs

If you are technically inclined, check your server's error logs and firewall settings around the time a scan occurs. The Broken Link Checker team has noted that some external services block their automated scans. If you see connection timeouts or blocks from the plugin's IP addresses, this confirms the issue is on the target server's side, not yours. In this case, you may need to manually mark these links as "Not broken" or dismiss the alert.

When All Else Fails

If a link is consistently reported as broken but works perfectly for real users, the most practical solution is to simply tell the plugin to ignore it. In the Broken Link Checker list, you can use the "Not broken" or "Dismiss" action for that specific link to prevent further false alerts.

By understanding the common causes and working through these steps, you can significantly reduce false 404 errors and make the Broken Link Checker plugin a more reliable tool for maintaining your website.

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