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Broken Scripts (404 / 5xx / Timeout)

One or more script URLs referenced by your site fail to load due to 404, 5xx, or timeout errors, breaking critical site functionality.

By Seoxpert Editorial · Published

Why it matters

Broken scripts can silently disable key site features, such as forms, navigation, analytics, or third-party integrations. This leads to poor user experience, failed conversions, and missing tracking data, all of which negatively impact SEO and business goals.

Impact

Unresolved broken scripts result in non-functional site features and lost analytics or conversion opportunities.

How it's detected

Automated crawlers detect broken scripts by checking for failed HTTP responses (404, 5xx, or timeouts) from script URLs referenced in the page source.

Common causes

  • Script file deleted or moved without updating references
  • Typo or incorrect path in the script src attribute
  • Third-party provider removed or changed the script URL
  • Network or CDN outages causing script timeouts
  • Build or deployment errors omitting script files

How to fix it

Open your browser's developer tools Network panel and reload affected pages to identify broken scripts (marked in red). Correct the script URL or remove the <script> tag if the script is no longer needed. For third-party scripts, contact the provider or replace with a working alternative. For self-hosted scripts, implement CI checks to catch broken script references before deployment.

Code examples

Broken script reference (404)

<!-- Broken: script file does not exist at this URL -->
<script src="/js/nonexistent.js"></script>

Fixed script reference

<!-- Fixed: script file exists at this URL -->
<script src="/js/app.js"></script>

FAQ

How do I find which scripts are broken on my site?

Use your browser's developer tools Network panel to reload each page and look for script requests that return 404, 5xx, or timeout errors.

What happens if a script fails to load?

Site features relying on that script will not work, often without visible errors to users or developers.

Should I remove or fix broken script tags?

Fix the URL if the script is needed; remove the tag if the script is obsolete.

How can I prevent broken scripts in the future?

Set up automated CI checks to fail builds when script references are broken, and use Subresource Integrity (SRI) for third-party scripts.

Found this issue on your site?

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