puppeteer/README.md
jrandolf f07ad2c661
fix: update documentation on configuring puppeteer (#9150)
This PR updates the docs regarding configuring puppeteer. In addition,
some changes have been made to the documentation generator to show
default values on the documentation site.

Also fixes: https://github.com/puppeteer/puppeteer/pull/9144
2022-10-24 09:07:05 +02:00

8.3 KiB

Puppeteer

Build status npm puppeteer package

Guides | API | FAQ | Contributing | Troubleshooting

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol. Puppeteer runs in headless mode by default, but can be configured to run in full (non-headless) Chrome/Chromium.

What can I do?

Most things that you can do manually in the browser can be done using Puppeteer! Here are a few examples to get you started:

  • Generate screenshots and PDFs of pages.
  • Crawl a SPA (Single-Page Application) and generate pre-rendered content (i.e. "SSR" (Server-Side Rendering)).
  • Automate form submission, UI testing, keyboard input, etc.
  • Create an automated testing environment using the latest JavaScript and browser features.
  • Capture a timeline trace of your site to help diagnose performance issues.
  • Test Chrome Extensions.

Getting Started

Installation

To use Puppeteer in your project, run:

npm i puppeteer
# or `yarn add puppeteer`
# or `pnpm i puppeteer`

When you install Puppeteer, it automatically downloads a recent version of Chromium (~170MB macOS, ~282MB Linux, ~280MB Windows) that is guaranteed to work with Puppeteer. For a version of Puppeteer without installation, see puppeteer-core.

Configuring Puppeteer

Puppeteer uses several defaults that can be customized through configuration files.

For example, to change the default cache directory Puppeteer uses to install browsers, you can add a .puppeteerrc.cjs (or puppeteer.config.cjs) at the root of your application with the contents

const {join} = require('path');

/**
 * @type {import("puppeteer").Configuration}
 */
module.exports = {
  // Changes the cache location for Puppeteer.
  cacheDirectory: join(__dirname, '.cache', 'puppeteer'),
};

After adding the configuration file, you will need to remove and reinstall puppeteer for it to take effect.

See Configuring Puppeteer for more information.

puppeteer-core

Every release since v1.7.0 we publish two packages:

puppeteer is a product for browser automation. When installed, it downloads a version of Chromium, which it then drives using puppeteer-core. Being an end-user product, puppeteer automates several workflows using reasonable defaults that can be customized.

puppeteer-core is a library to help drive anything that supports DevTools protocol. Being a library, puppeteer-core is fully driven through its programmatic interface implying no defaults are assumed and puppeteer-core will not download Chromium when installed.

You should use puppeteer-core if you are connecting to a remote browser or managing browsers yourself. If you are managing browsers yourself, you will need to call puppeteer.launch with an an explicit executablePath (or channel if it's installed in a standard location).

When using puppeteer-core, remember to change the import:

import puppeteer from 'puppeteer-core';

Usage

Puppeteer follows the latest maintenance LTS version of Node.

Puppeteer will be familiar to people using other browser testing frameworks. You launch/connect a browser, create some pages, and then manipulate them with Puppeteer's API.

For more in-depth usage, check our guides and examples.

Example

The following example searches developers.google.com/web for articles tagged "Headless Chrome" and scrape results from the results page.

import puppeteer from 'puppeteer';

(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();

  await page.goto('https://developers.google.com/web/');

  // Type into search box.
  await page.type('.devsite-search-field', 'Headless Chrome');

  // Wait for suggest overlay to appear and click "show all results".
  const allResultsSelector = '.devsite-suggest-all-results';
  await page.waitForSelector(allResultsSelector);
  await page.click(allResultsSelector);

  // Wait for the results page to load and display the results.
  const resultsSelector = '.gsc-results .gs-title';
  await page.waitForSelector(resultsSelector);

  // Extract the results from the page.
  const links = await page.evaluate(resultsSelector => {
    return [...document.querySelectorAll(resultsSelector)].map(anchor => {
      const title = anchor.textContent.split('|')[0].trim();
      return `${title} - ${anchor.href}`;
    });
  }, resultsSelector);

  // Print all the files.
  console.log(links.join('\n'));

  await browser.close();
})();

Default runtime settings

1. Uses Headless mode

Puppeteer launches Chromium in headless mode. To launch a full version of Chromium, set the headless option when launching a browser:

const browser = await puppeteer.launch({headless: false}); // default is true

2. Runs a bundled version of Chromium

By default, Puppeteer downloads and uses a specific version of Chromium so its API is guaranteed to work out of the box. To use Puppeteer with a different version of Chrome or Chromium, pass in the executable's path when creating a Browser instance:

const browser = await puppeteer.launch({executablePath: '/path/to/Chrome'});

You can also use Puppeteer with Firefox Nightly (experimental support). See Puppeteer.launch for more information.

See this article for a description of the differences between Chromium and Chrome. This article describes some differences for Linux users.

3. Creates a fresh user profile

Puppeteer creates its own browser user profile which it cleans up on every run.

Using Docker

See our guide on using Docker.

Using Chrome Extensions

See our guide on using Chrome extensions.

Resources

Contributing

Check out our contributing guide to get an overview of Puppeteer development.

FAQ

Our FAQ has migrated to our site.