Lighthouse Score

A Lighthouse Score is a comprehensive performance metric generated by Google’s open-source tool, Lighthouse, which analyzes web pages and provides scores across multiple categories to help developers improve their websites’ quality.

Key Performance Categories

Lighthouse evaluates websites across four main categories, each scored from 0 to 100:

1. Performance: Measures loading speed, interactivity, and visual stability
2. Accessibility: Evaluates how well the site works for users with disabilities
3. Best Practices: Checks adherence to modern web development standards
4. SEO: Assesses search engine optimization fundamentals

How to Access Lighthouse

The most common ways to access Lighthouse include:

• Using Google PageSpeed Insights, which provides both mobile and desktop analysis
• Through Chrome DevTools (F12 > Lighthouse tab)
• Via command-line interface (CLI)
• As a Node module for automated testing

Understanding the Scores

Performance Metrics

• First Contentful Paint (FCP)
• Largest Contentful Paint (LCP)
• Total Blocking Time (TBT)
• Cumulative Layout Shift (CLS)
• Speed Index
• Time to Interactive (TTI)

Common Issues That Affect Scores

• Unoptimized images
• Render-blocking resources
• Excessive JavaScript
• Poor server response times
• Unused CSS/JavaScript
• Missing meta tags

Best Practices for Improvement

To achieve better Lighthouse scores:

• Optimize and compress images
• Implement proper caching strategies
• Minimize third-party code
• Enable text compression
• Use modern image formats
• Implement lazy loading
• Remove unused code
• Follow accessibility guidelines

Understanding and monitoring your Lighthouse scores is crucial for maintaining a high-quality website that provides an excellent user experience. Regular testing and optimization based on Lighthouse recommendations can significantly improve your site’s performance and visibility.