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Troubleshoot File Optimization and PageSpeed Verification ​

This guide covers common troubleshooting scenarios when using Super Page Cache Pro file optimization settings: Asset Manager exclusions not appearing in PageSpeed Insights, missing CSS minification controls, JS defer with no visible effect, and confusing results when running SiteGround CDN alongside Cloudflare.

Verify Asset Manager changes before retesting PageSpeed ​

After disabling a script or style in the Asset Manager, the change will not be visible until you purge the page cache. PageSpeed Insights may also return a stale result if it reads a previously cached response. Follow these steps to confirm the change is active before retesting:

  1. In your WordPress dashboard, go to Super Page Cache > Dashboard and click Purge Everything.
  2. Open an incognito/private browser window.
  3. Open DevTools > Network.
  4. Reload the page you want to test.
  5. In the Network tab, search for the script or style URL you disabled (for example, the Google Maps API URL).
    • If the asset is absent from the request list, the exclusion rule is active.
    • If the asset still appears, check that the rule is saved and that you purged the correct cache layer.
  6. Click the main HTML document request and inspect its response headers. Confirm:
    • X-WP-CF-Super-Cache-Active: 1 — Super Page Cache served the page.
    • X-Wp-Spc-Disk-Cache: HIT — the disk cache was used.
    • CF-Cache-Status: HIT — Cloudflare served the response from its edge cache.
  7. Run the plugin's built-in Test Cache tool on the Dashboard to confirm caching is active.

📝 Note: If any header shows MISS or EXPIRED, reload the page once or twice to let Cloudflare populate its edge cache before retesting.

Once you have confirmed the asset change is active in the Network tab, you can run PageSpeed Insights for a reliable score.

📝 Note: PageSpeed Insights can return scores based on cached crawl data, particularly for recently changed pages. It is not an immediate real-time validation tool. After a cache purge, verify your changes are live using the browser Network tab first, then use PageSpeed Insights to measure the score impact.

CSS optimization expectations ​

Super Page Cache Pro includes Remove Unused CSS, which strips CSS rules that are not used on a given page. However, Super Page Cache Pro does not currently provide CSS minification or CSS grouping (combining multiple stylesheets into one file).

If you specifically need CSS minification or file combining, use a dedicated optimization plugin such as Autoptimize or Asset CleanUp. Be careful not to enable page caching in two plugins at the same time — keep page caching handled only by Super Page Cache.

📝 Info: Remove Unused CSS reduces CSS payload size by removing unused rules. CSS minification removes whitespace and comments from files. CSS grouping combines multiple files into one request. These are separate operations and require separate tools.

Why JS defer/delay may not change every script ​

Defer Javascript and Delay Javascript do not affect all scripts on every page. Certain script types are intentionally skipped:

  • Inline scripts (JavaScript written directly in the page HTML rather than loaded from a file) are not deferred or delayed by default.
  • Module scripts (type="module") are natively deferred by the browser and are not processed by the plugin.
  • Essential scripts — some third-party scripts, payment widgets, or anti-fraud libraries actively resist deferral and may revert to synchronous loading.
  • Scripts excluded via Exclude JS — any handles or URLs you add to the exclusion list are skipped intentionally.

If deferring or delaying JavaScript appears to make no visible difference in PageSpeed Insights, verify using the browser Network tab that JS files are actually being loaded deferred. If the change breaks menus, forms, carts, sliders, maps, or other interactive elements, use Exclude JS to exempt the affected scripts, or use Exclude Pages to disable JS optimization on specific URLs.

Avoid conflicting CDN layers ​

Running SiteGround CDN and Cloudflare CDN (or Cloudflare page caching) at the same time creates a layered cache stack that can make purging and verification confusing. When both layers are active, a purge in Super Page Cache may clear one layer but not the other, so stale content can still be served and test results will be inconsistent.

Recommendations:

  • Choose one CDN layer: either Cloudflare (recommended if you use the Super Page Cache Cloudflare integration) or SiteGround CDN — not both.
  • The Super Page Cache > Settings > Third Party > SiteGround SuperCacher integration is specifically for server-cache purge synchronization with SiteGround's server-side cache. It is not required if you are already using Cloudflare for CDN delivery.
  • If you deliberately use both layers, you must manually purge each one separately and verify headers from each layer before drawing conclusions about cache behavior.

⚠️ Warning: Using SiteGround CDN and Cloudflare simultaneously can produce misleading headers during verification. For example, CF-Cache-Status: HIT may indicate Cloudflare served a response that SiteGround CDN had already cached, making it difficult to determine which layer actually delivered the page.

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