Server & Network

Core Web Vitals & Speed Test

Measure a website's Core Web Vitals metrics and Google PageSpeed performance score for free. See LCP, CLS, INP, FCP, and Speed Index values all in one place.

Core Web Vitals & PageSpeed Analysis
Information

About Core Web Vitals & Speed Test

Core Web Vitals are a set of key performance metrics that Google uses to evaluate the user experience of web pages. These metrics numerically express page load speed, visual stability, and interaction response time. Since Google uses these metrics directly as search ranking signals, a good score is critical for both user satisfaction and SEO.

This free tool uses the Google PageSpeed Insights v5 Public API to crawl the URL you enter in real time. LCP (Largest Contentful Paint) how long it takes for the main content of the page to load, CLS (Cumulative Layout Shift) how much the visual elements shift, INP (Interaction to Next Paint) It measures the response time to interactions such as clicks and touches. FCP (First Contentful Paint) the browser's initial content rendering time, Speed Index This shows how quickly the visible content is populated.

The results are presented separately as lab data (Lighthouse simulation) and, if available, real user experience (CrUX/field) data. This tool one-time It provides a real-time measurement; regular trend tracking requires a cron job and database infrastructure. Since Google PageSpeed Public API keyless usage has a daily limit of approximately 400 requests, you may encounter limit errors during peak hours; in such a case, the tool will inform you.

How to use it?

Step by step

  1. The address of the site you want to test https://example.com Enter it in this format.
  2. Mobile or Desktop Choose your strategy (default is Mobile; Google ranking signal is mobile-based).
  3. Analyze Click the button — the API call may take approximately 5-20 seconds.
  4. Performance score ring...followed by LCP, CLS, INP, FCP, Speed Index and TBT metric cards It is visible through the color threshold.
  5. If any Real User Data (CrUX) This section displays actual user metrics from the past 28 days.
FAQ

Frequently Asked Questions

Core Web Vitals consists of LCP, CLS, and INP (formerly FID) metrics, which Google has been using as search ranking signals since 2021. These three metrics measure page loading speed, visual stability, and interaction response time. Good scores improve user experience and positively contribute to organic rankings.

Google's defined thresholds are: Good ≤2.5 sec / Medium ≤4 sec for LCP; Good ≤0.1 sec / Medium ≤0.25 sec for CLS; Good ≤200 ms / Medium ≤500 ms for INP. Staying below these values will place you in the 'Good' category.

Lab data is a measurement simulated by Lighthouse in a controlled environment; it is deterministic and reproducible. Field (CrUX) data, on the other hand, is a 28-day average of real-world measurements collected by Google from Chrome users. CrUX data is only provided for URLs/origins with sufficient traffic.

The Google PageSpeed Public API allows a daily limit of approximately 400 free requests; exceeding this limit will result in a 'limit reached' message. Additionally, very slow or inaccessible sites may experience API timeouts. Sites with redirect loops or robot blockers may also encounter errors.

PageSpeed scores are calculated using a Lighthouse-weighted formula and can vary from measurement to measurement depending on network conditions, server response times, and page changes. For a stable measurement, it is recommended to test the same page several times and take the average. This tool performs a single, instantaneous measurement.
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