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PageSpeed Insights Integration

4 min read

xSpeed Cache can run Google PageSpeed Insights audits on your pages from inside the dashboard. You get a performance score and the top issues to fix, without leaving WordPress.

What this does

This panel calls Google’s PageSpeed Insights (PSI) API on demand for a URL you choose. It then shows:

  • A performance score from 0 to 100.
  • Core Web Vitals and lab metrics for the page: LCP, FCP, CLS, TBT (Total Blocking Time), Speed Index, and TTFB.
  • The top issues, ranked by how much time they could save.

Each result is cached for 24 hours per URL and strategy pair, so re-showing the last audit does not spend more of your quota. You can force a fresh run when you want one.

Why use it

PageSpeed Insights is the lab audit Google publishes for measuring page performance. Running it from the dashboard keeps your testing in one place and lets you re-check a page after changing cache or optimization settings.

Requirements

  • xSpeed Cache Pro must be active. The PageSpeed Insights integration is a Pro feature.
  • An internet connection, since the audit runs on Google’s servers.
  • A Google PSI API key is optional but recommended for frequent use (see below).

How to run an audit

  1. Open the xSpeed Cache dashboard and go to the PageSpeed panel (the gauge icon).
  2. Choose the URL to audit. The site home page is used if you do not specify one.
  3. Pick a strategy, Mobile or Desktop. Mobile is the default.
  4. Run the audit. The score, metrics, and top issues appear when Google responds.
  5. To get fresh numbers within the 24-hour cache window, force a new run.

The URL must include http:// or https://.

Settings explained

SettingWhat it doesDefault
PageSpeed Insights API Key (optional)Your own Google PSI key for a higher request limit.Empty
Default StrategyWhether audits default to Mobile or Desktop.Mobile

PageSpeed Insights API Key (optional). Audits work without a key, but Google rate-limits anonymous calls to roughly one request per second site-wide. Adding your own free key raises the limit to about 25,000 requests per day. You can create a free key in the Google Cloud Console under Credentials.

Default Strategy. Google ranks pages on their mobile experience, so Mobile is the recommended default. You can still override the strategy for an individual audit from the dashboard.

Reading the result

  • Score (0–100) — Google’s overall performance score for the page. Higher is better.
  • Metrics — LCP, FCP, CLS, TBT, Speed Index, and TTFB, in milliseconds (CLS is unitless). A metric may show as not available if Google did not return it.
  • Top issues — the audits with the biggest potential savings, each with a title, a description, and an estimated time saving in milliseconds. The dashboard surfaces the top few with an option to see more.

Note: Results are cached for 24 hours per URL and strategy. If you run the same URL and strategy again within that window, you get the cached result unless you force a fresh run.

Best practices

  • Add your own free API key if you plan to run audits often or across many URLs. It avoids the anonymous rate limit.
  • Audit on Mobile first, since that is what Google uses for ranking.
  • Re-run an audit after changing cache or optimization settings to see the effect. Force a fresh run so you are not reading the cached score.
  • Work through the top issues in order. They are sorted by estimated savings.

Troubleshooting

The audit fails or times out. The audit runs on Google’s servers and depends on your site being reachable from the internet. Local or password-protected sites cannot be audited. Check the error message returned in the result.

I am getting rate-limited. Anonymous PSI calls are limited to about one per second site-wide. Add your own free API key to raise the limit.

The score did not change after I made a fix. Results are cached for 24 hours. Force a fresh run to re-audit the page.

A metric shows as not available. Google did not return that metric for this page. Try re-running the audit.

FAQ

Do I need an API key? No. Audits work without one. A key is only needed to raise the request limit for frequent use.

Mobile or Desktop — which should I use? Mobile, in most cases. Google ranks on the mobile experience. Use Desktop when you specifically want to check the desktop view.

How is this different from Real-User Monitoring? PageSpeed Insights is a single lab audit you run on demand. Real-User Monitoring measures real visitors over time. Use both for a full picture.

  • Real-User Monitoring (Core Web Vitals)
  • Performance Recommendations
  • Reading the Cache Health Dashboard