Lighthouse desde la CLI y mediante programación
Aprenda a ejecutar auditorías de Lighthouse desde la línea de comandos e integrar su API en scripts y aplicaciones personalizados.
Lighthouse desde la CLI y mediante programación es una lección gratuita de Web Performance Optimization & Lighthouse en CoddyKit. Esta es la lección 1 de 4. Puedes leer la lección completa abajo gratuitamente — luego la practicas en el navegador con un editor de código integrado y un tutor de IA 24/7. Forma parte de la ruta de aprendizaje de Web Performance Optimization & Lighthouse, y tu progreso se sincroniza en la web y la app de CoddyKit. El curso de Web Performance Optimization & Lighthouse incluye 4 lecciones en total.
Partes de esta lección aún no han sido traducidas y se muestran en inglés.
Beyond the Browser
You've likely used Lighthouse in your browser's DevTools. But what if you want to run audits automatically or integrate them into your workflow?
This lesson explores how to use Lighthouse from the command line (CLI) for quick checks and programmatically via its Node.js API for advanced automation.
Automate & Integrate
Running Lighthouse from the CLI or programmatically opens up powerful possibilities:
- Automation: Schedule regular audits without manual intervention.
- CI/CD Integration: Catch performance regressions early in your development pipeline.
- Custom Reports: Generate reports tailored to your specific needs.
- Large-Scale Testing: Audit many pages efficiently across a website.
Get Lighthouse CLI
To use Lighthouse from the command line, you need Node.js installed on your system. Once Node.js is ready, you can install the Lighthouse CLI globally using npm:
npm install -g lighthouse
This command makes the lighthouse command available directly in your terminal, allowing you to run audits from any directory.
Run a Basic CLI Audit
With Lighthouse CLI installed, running an audit is straightforward. Just provide the URL you want to test. By default, it outputs a summary to the console and generates an HTML report.
lighthouse https://www.example.com
This will launch a headless Chrome instance, run the audit, and then generate an HTML report file in your current directory named after the URL.
Choose Your Output
The Lighthouse CLI can generate reports in different formats. You can specify the output type and path using flags:
--output html: Generates a user-friendly HTML report (default).--output json: Provides raw audit data in JSON format for parsing.--output csv: Exports a summary of key metrics as a CSV file.
Try running an audit and saving the output as JSON:
lighthouse https://www.example.com --output json --output-path ./report.json
Customize Your Audit
You can fine-tune your audits with various options to simulate different user conditions or focus on specific aspects:
--throttling-preset: Simulates different network and CPU conditions (e.g.,mobile,desktop).--only-categories: Focuses the audit on specific categories (e.g.,performance,accessibility).
Example: Audit only performance for a desktop user:
lighthouse https://www.example.com --throttling-preset desktop --only-categories performance
Lighthouse as an API
For deeper integration and more control, Lighthouse offers a Node.js API. This allows you to embed Lighthouse directly into your JavaScript applications, giving you full control over the audit process and access to the raw results.
It typically uses Puppeteer, a Node library, to programmatically control a headless Chrome browser instance for the audit.
Basic Programmatic Audit
Let's create a simple Node.js script to run a Lighthouse audit. First, ensure you have lighthouse and chrome-launcher installed in your project:
npm install lighthouse chrome-launcher
Then, create a .js file (e.g., audit.js) with the following code:
const lighthouse = require('lighthouse');
const chromeLauncher = require('chrome-launcher');
async function runLighthouseAudit(url) {
// Launch a headless Chrome instance
const chrome = await chromeLauncher.launch({
chromeFlags: ['--headless']
});
// Configure Lighthouse options
const options = {
logLevel: 'info',
output: 'json',
port: chrome.port // Connect to the launched Chrome instance
};
// Run Lighthouse audit
const runnerResult = await lighthouse(url, options);
console.log('Audit complete for %s', runnerResult.lhr.finalUrl);
console.log('Performance score: %s', runnerResult.lhr.categories.performance.score * 100);
// Kill the Chrome instance
await chrome.kill();
}
// Call the function with a URL to audit
runLighthouseAudit('https://www.example.com');Extracting Audit Data
The runnerResult object contains a wealth of data about the audit (lhr stands for Lighthouse Result). You can programmatically access scores, specific audit details, and more.
Here's how to extract the Performance score and First Contentful Paint (FCP) value from the results:
const lighthouse = require('lighthouse');
const chromeLauncher = require('chrome-launcher');
async function extractAuditData(url) {
const chrome = await chromeLauncher.launch({
chromeFlags: ['--headless']
});
const options = {
port: chrome.port
};
const runnerResult = await lighthouse(url, options);
// Access the overall performance score
const performanceScore = runnerResult.lhr.categories.performance.score * 100;
// Access a specific audit result by its ID (e.g., First Contentful Paint)
const fcpAudit = runnerResult.lhr.audits['first-contentful-paint'];
console.log(`Performance Score: ${performanceScore}%`);
console.log(`First Contentful Paint: ${fcpAudit.displayValue}`);
await chrome.kill();
}
extractAuditData('https://www.example.com');When to Use What?
You've learned about both CLI and programmatic Lighthouse. Which of the following are ideal use cases for using Lighthouse programmatically (via its Node.js API)?
Recap: CLI & API Power
Great job! You've explored the power of Lighthouse beyond the browser.
- The Lighthouse CLI is perfect for quick, on-demand audits and simple report generation directly from your terminal.
- The Lighthouse Node.js API provides deep integration capabilities, enabling automation, custom reporting, and embedding performance checks into complex applications and workflows.
These tools are essential for maintaining and improving web performance at scale and integrating audits into your development process.
Preguntas frecuentes
¿La lección «Lighthouse desde la CLI y mediante programación» es gratis?
Sí — el texto completo de «Lighthouse desde la CLI y mediante programación» es gratis para leer aquí en la web. Para practicarla de forma interactiva (editor de código integrado y tutor de IA 24/7) y desbloquear el resto del curso de Web Performance Optimization & Lighthouse, actualiza a CoddyKit PRO. El curso de Web Performance Optimization & Lighthouse incluye 4 lecciones en total.
¿Qué aprenderé en «Lighthouse desde la CLI y mediante programación»?
Aprenda a ejecutar auditorías de Lighthouse desde la línea de comandos e integrar su API en scripts y aplicaciones personalizados. Practicas Web Performance Optimization & Lighthouse con código real que ejecutas directamente en el navegador, y un tutor de IA 24/7 responde tus preguntas mientras trabajas en la lección.
¿Necesito experiencia previa para empezar Web Performance Optimization & Lighthouse?
No se requiere experiencia previa. Web Performance Optimization & Lighthouse en CoddyKit está estructurado para principiantes hasta estudiantes avanzados, así que puedes empezar aquí o desde el inicio y avanzar a tu ritmo. Esta es la lección 1 de 4.
¿Cuánto tiempo toma la lección «Lighthouse desde la CLI y mediante programación»?
La mayoría de las lecciones de CoddyKit toman alrededor de 5–10 minutos. Cada una es compacta e interactiva, así que avanzas constantemente y retomas exactamente por donde dejaste en la web y la app.
¿Puedo escribir y ejecutar código en esta lección de Web Performance Optimization & Lighthouse?
Sí. Cada lección de Web Performance Optimization & Lighthouse incluye un editor de código integrado, así que escribes y ejecutas código real directamente en tu navegador y obtienes retroalimentación instantánea de IA — sin configuración local necesaria.
Todas las lecciones de este curso
- Lighthouse desde la CLI y mediante programación
- Auditorías y aserciones personalizadas
- Integración de Lighthouse en CI/CD
- Presupuestos de rendimiento con Lighthouse