Page Speed Checker

About Page Speed Checker

The Page Speed Checker is a browser-based tool that analyzes website performance by measuring load timing and auditing HTTP response headers. It provides an instant performance score, a visual waterfall chart of timing phases (DNS, connection, TTFB, download), and actionable recommendations for improving page speed, caching, compression, and security headers.

How to Use the Page Speed Checker

1. Enter the URL — Type or paste the full URL of the page you want to analyze. The tool auto-adds https:// if omitted.
2. Click "Analyze Speed" — The tool fetches the page, records timing, and analyzes response headers.
3. Review Your Score — An overall performance score (0–100) is calculated based on response time and header best practices.
4. Check the Waterfall — The visual waterfall chart breaks down DNS lookup, connection, server response (TTFB), and content download phases.
5. Read Audit & Recommendations — Review specific header audit results and follow priority-ranked recommendations to improve performance.

Understanding Key Metrics

TTFB (Time to First Byte)

TTFB measures how long the browser waits for the first byte of data from the server after sending the request. It includes DNS resolution, TCP connection, TLS handshake, and server processing time. A good TTFB is under 200ms; values over 1000ms indicate serious server-side bottlenecks.

Total Load Time

The total time from the start of the request to the completion of the response download. For HTML documents, this represents the document transfer time (not including subsequent resource loading like images, CSS, and JavaScript).

Response Size

The size of the response body. Smaller responses load faster. Enable compression (gzip/Brotli) and minify HTML/CSS/JS to reduce transfer size. A typical web page HTML should be under 100KB compressed.

Performance Header Best Practices

Score Breakdown

The performance score is calculated from two main factors:

• Response Time (60%) — TTFB and total load time. Under 200ms TTFB and under 1000ms total is excellent.
• Header Audit (40%) — Missing compression, caching, or security headers reduce your score. Each failed check deducts points.

Scores are classified as: 90–100 Excellent, 70–89 Good, 50–69 Needs Improvement, 0–49 Poor.

Limitations

• This tool runs in your browser, so results reflect your network conditions and geographic location.
• CORS restrictions may prevent full header analysis on some websites. The tool falls back to timing-only analysis in these cases.
• Unlike server-side tools (Lighthouse, WebPageTest), this tool cannot measure render timing, JavaScript execution, or Core Web Vitals like LCP, FID, and CLS.
• Results may vary between runs due to network conditions, server load, and caching.

Tips for Improving Page Speed

1. Enable Compression — Configure gzip or Brotli on your web server to compress text-based assets.
2. Set Cache Headers — Use long max-age for static assets and short max-age with ETag for HTML.
3. Use a CDN — Serve assets from edge locations close to your users to reduce latency.
4. Optimize Images — Use modern formats (WebP, AVIF), compress images, and implement lazy loading.
5. Minimize Render-Blocking Resources — Defer non-critical CSS and JavaScript.
6. Reduce Third-Party Scripts — Each external script adds DNS lookups, connections, and parsing time.

FAQ

What does the Page Speed Checker measure?

It measures response time (TTFB and total load), analyzes HTTP response headers for performance best practices like caching, compression, and security headers, and provides an overall performance score with actionable recommendations.

Why is page speed important for SEO?

Google uses page speed as a ranking factor. Faster pages provide better user experience, lower bounce rates, and higher conversion rates. Core Web Vitals, which include loading performance, are part of Google's page experience signals.

What is TTFB and why does it matter?

TTFB (Time to First Byte) measures how long the browser waits for the first byte of data from the server. A good TTFB is under 200ms. High TTFB indicates server-side performance issues like slow database queries, lack of caching, or overloaded servers.

Why do I get CORS errors when testing some URLs?

CORS (Cross-Origin Resource Sharing) errors occur when a website restricts browser-based requests from other domains. This is a security feature. If you encounter CORS errors, the target server does not allow cross-origin requests from browsers.

How can I improve my page speed score?

Enable gzip or Brotli compression, set proper Cache-Control headers with long max-age values, use a CDN, optimize images, minimize render-blocking resources, and implement security headers like HSTS and X-Content-Type-Options.