Free Tools in This Category
Page Speed Test
Analyze website loading performance, total page asset weight, request counts, and load bottlenecks.
Check Gzip Compression
Verify whether Gzip or Brotli text compression is properly enabled on your web server.
Get Http Headers
Inspect server response headers, caching directives (Cache-Control, ETag), and HTTP/2 or HTTP/3 transport status.
The Three Core Web Vitals Metrics That Define Google User Experience
In 2021, Google officially rolled out the Page Experience Update, making Core Web Vitals a confirmed ranking signal. These metrics measure real-world user perceived loading performance, interactivity, and visual stability:
| Core Web Vital | What It Measures | Good Score Threshold | Primary Fix Action |
|---|---|---|---|
| Largest Contentful Paint (LCP) | Perceived Loading Speed: When the main hero image or text block finishes rendering | ≤ 2.5 seconds | Compress hero images, preload critical web fonts, use edge CDN caching |
| Interaction to Next Paint (INP) | Responsiveness: How quickly the page visually updates after a user clicks or taps | ≤ 200 milliseconds | Break up long JavaScript tasks, defer non-essential third-party analytics scripts |
| Cumulative Layout Shift (CLS) | Visual Stability: Unexpected layout jumping while banners or fonts load | ≤ 0.1 | Always set explicit width and height attributes on images and video embeds |
Tool-by-Tool Guide to Performance Tools
1. Page Speed Test: Comprehensive Load Diagnostic
The Page Speed Test examines every asset downloaded during page rendering:
- Time to First Byte (TTFB): Measures how many milliseconds your origin server takes to process the PHP/database request and send the first byte of HTML back to the browser.
- Asset Size Breakdown: Visualizes the percentage of total page weight consumed by HTML, CSS stylesheets, JavaScript bundles, web fonts, and images.
- Total HTTP Requests: Audits the number of external round trips required before the page is fully interactive.
2. Check Gzip Compression: Slashing 70% of Text Payload
Text files (HTML, CSS, JavaScript, SVG, and JSON) contain massive amounts of repetitive strings, tags, and whitespace. Modern web servers can compress these text files using Gzip or Brotli algorithms on the fly before sending them over the network.
The Check Gzip Compression tool inspects your server's Content-Encoding header:
- Uncompressed CSS bundle: 120 KB
- Gzip compressed transfer: 28 KB (76.6% bandwidth savings!)
3. Get HTTP Headers: Inspecting Server Cache Directives
Efficient browser caching prevents returning visitors from re-downloading static CSS, JS, and image files repeatedly. The Get Http Headers tool reveals your caching configuration:
Cache-Control: max-age=31536000, immutable(Ideal for versioned static assets).ETag&Last-Modified(Validates client cache freshness with lightweight 304 Not Modified responses).X-Content-Type-Options: nosniffandStrict-Transport-Security(Crucial HTTP security headers).