How to Use Google Lighthouse for Technical SEO

Google Lighthouse is an open-source, automated tool for improving the quality of web pages. It provides audits for performance, accessibility, progressive web apps, SEO, and more. By leveraging Google Lighthouse, you can gain valuable insights into your website’s technical SEO health and identify areas for improvement. This guide will walk you through how to use Google Lighthouse for technical SEO.

What is Google Lighthouse?

Google Lighthouse is a powerful tool that runs a series of audits on your website and generates a report detailing various performance metrics and recommendations. It helps you understand how your site performs in several key areas and provides actionable advice to enhance your site’s SEO, speed, and overall user experience.

Why Use Google Lighthouse for SEO?

• Comprehensive Audits: Lighthouse covers a broad range of metrics, from basic SEO checks to advanced performance insights.
• Actionable Recommendations: The tool provides specific recommendations on how to improve each metric.
• Performance Tracking: Regular use allows you to track performance improvements over time.
• Free and Easy to Use: Lighthouse is freely available and can be used via the Chrome DevTools, command line, or as a Node module.

How to Run Google Lighthouse

Using Chrome DevTools

1. Open Chrome DevTools: Open your website in the Chrome browser. Right-click on the page and select “Inspect” to open DevTools.
2. Navigate to Lighthouse: In the DevTools panel, navigate to the “Lighthouse” tab.
3. Configure Audits: Select the categories you want to audit (Performance, Accessibility, Best Practices, SEO, and PWA). For SEO, ensure the “SEO” category is checked.
4. Run the Audit: Click “Generate Report” to start the audit. Lighthouse will run a series of tests and generate a report.

Using the Lighthouse CLI

Install Lighthouse: Install Lighthouse globally using npm:
bash
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npm install -g lighthouse

Run Lighthouse: Use the following command to run Lighthouse on your URL:
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lighthouse https://www.example.com –output html –output-path ./report.html

2. View the Report: Open the generated HTML report in your browser to view the results.

Using the Lighthouse Node Module

Install Lighthouse: Install the Lighthouse Node module:
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npm install –save lighthouse

Write a Script: Create a JavaScript file to run Lighthouse:
javascript
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const lighthouse = require(‘lighthouse’);

const chromeLauncher = require(‘chrome-launcher’);

(async () => {

  const chrome = await chromeLauncher.launch({chromeFlags: [‘–headless’]});

  const options = {logLevel: ‘info’, output: ‘html’, onlyCategories: [‘seo’], port: chrome.port};

  const runnerResult = await lighthouse(‘https://www.example.com’, options);

  // `.report` is the HTML report as a string

  const reportHtml = runnerResult.report;

  console.log(reportHtml);

  await chrome.kill();

})();

Run the Script: Execute the script using Node.js:
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node your-script.js

Key SEO Metrics and Recommendations in Google Lighthouse

1. SEO Basics

Checks:

• Meta Descriptions: Ensure every page has a unique meta description.
• Title Elements: Verify that each page has a unique and descriptive title.
• Viewport: Check if the viewport meta tag is set for responsive design.
• Document Validity: Ensure the HTML is valid.

Recommendations:

• Write concise and relevant meta descriptions for each page.
• Use unique and descriptive titles that include primary keywords.
• Implement a viewport meta tag to ensure responsive design.
• Validate HTML to avoid errors that might affect crawling and indexing.

2. Mobile Friendliness

Checks:

• Font Sizes: Ensure text is legible on small screens.
• Tap Targets: Verify that buttons and links are appropriately sized and spaced for touch interaction.

Recommendations:

• Use relative units (e.g., em, rem) for font sizes to ensure scalability.
• Ensure tap targets are at least 48×48 pixels and have sufficient spacing.

3. Crawlability

Checks:

• Robots.txt: Ensure the robots.txt file is present and correctly configured.
• Links: Check for broken links and ensure internal linking is effective.

Recommendations:

• Create and correctly configure a robots.txt file to guide search engine crawlers.
• Regularly audit your site for broken links and fix them to maintain a healthy link structure.

4. Structured Data

Checks:

• Structured Data: Ensure structured data is implemented correctly using schema.org standards.

Recommendations:

• Implement structured data to enhance search results with rich snippets.
• Use the structured data testing tool to validate your markup.

5. Performance

Checks:

• First Contentful Paint (FCP): Measure the time it takes for the first content to be visible.
• Time to Interactive (TTI): Measure the time it takes for the page to become fully interactive.
• Speed Index: Measure how quickly the content is visually displayed.

Recommendations:

• Optimize images and other media by compressing and using modern formats.
• Minify CSS, JavaScript, and HTML to reduce file sizes.
• Implement lazy loading for images and videos to improve initial load times.

6. Accessibility

Checks:

• Color Contrast: Ensure text has sufficient contrast against the background.
• Alt Text: Verify that all images have descriptive alt text.

Recommendations:

• Use tools like the WebAIM Contrast Checker to ensure color contrast ratios meet accessibility standards.
• Add descriptive alt text to all images to improve accessibility and SEO.

Interpreting and Acting on Lighthouse Reports

Analyzing Scores

Lighthouse provides scores for each category (Performance, Accessibility, Best Practices, SEO, and PWA) on a scale from 0 to 100. Aim for high scores in all categories, especially SEO.

Prioritizing Issues

Focus on critical issues that have the most significant impact on SEO and user experience. Lighthouse categorizes issues as Opportunities, Diagnostics, and Passed Audits, making it easier to prioritize.

Implementing Recommendations

Follow the actionable recommendations provided by Lighthouse to address identified issues. Regularly audit your site using Lighthouse to ensure ongoing optimization.

Monitoring Improvements

Track your scores and improvements over time to gauge the effectiveness of your changes. Use Google Analytics and Google Search Console to monitor the impact on traffic, rankings, and user engagement.

Google Lighthouse is a valuable tool for enhancing your website’s technical SEO. By regularly auditing your site with Lighthouse and implementing its recommendations, you can improve page load speed, mobile friendliness, crawlability, structured data, and overall user experience. Consistently monitoring and optimizing your site based on Lighthouse reports will help you achieve better search engine rankings and provide a superior experience for your users.