Is a performance issue often reported in a site audit within Semrush. This issue appears when browsers are not instructed to store static files for reuse.
JavaScript and CSS files control how a website looks and behaves. When these files are not cached, browsers must reload them every time a user visits a new page.
Fixing caching improves load speed across the entire site and reduces repeated requests.
What is Uncached JavaScript and CSS Files?
Uncached JavaScript and CSS files are static files that are not stored in a visitor’s browser after the first load.
Normally, browsers cache these files so they can reuse them when a user navigates between pages. This reduces the amount of data that needs to be downloaded repeatedly.
When caching is not enabled, the browser must request and reload the same files on every page. This increases load time and server requests.
This issue often appears across many pages because the same files are used sitewide.
Why does Uncached JavaScript and CSS Files affect SEO?
Uncached files increase page load time, which affects user experience and site performance.
Search engines such as Google consider performance as part of overall site quality. When pages load slowly, users are more likely to leave before interacting with the content.
The issue does not directly impact rankings on its own. However, slower performance can reduce engagement and efficiency across the site.
Caching allows browsers to reuse files, which improves speed and consistency.
How do I fix Uncached JavaScript and CSS Files?
Fixing this issue depends on whether the files are controlled by your website.
Follow these steps.
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Review the flagged files in your audit report.
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Check the file source.
Confirm whether the JavaScript or CSS files are hosted on your domain.
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Ignore external files when necessary.
If files come from third-party sources, such as fonts or plugins hosted elsewhere, you cannot control their caching.
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Enable browser caching for internal files.
Configure caching rules on your server to store static files.
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Use hosting-level optimization.
Managed hosts like SiteGround provide built-in caching tools that handle this automatically.
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Use a plugin if needed.
In WordPress, install a performance plugin that enables browser caching and file optimization.
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Avoid manual code edits unless experienced.
Directly modifying JavaScript or CSS files can break site functionality.
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Test your website after changes.
Ensure pages load correctly and no features are broken.
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Re-run the audit in Semrush to confirm the issue is resolved.
