Implementation:Puppeteer Puppeteer Browsers Launch

Knowledge Sources	Puppeteer
Domains	Browser_Management, Process_Management
Last Updated	2026-02-11 23:00 GMT

Overview

Concrete tool for spawning and managing browser processes, provided by the @puppeteer/browsers package.

Description

The launch() function spawns a browser process and returns a Process object for lifecycle management. The Process class wraps Node.js child_process.ChildProcess with convenience methods for WebSocket endpoint detection, graceful shutdown, and signal handling.

Usage

Call this function with an executable path and arguments to spawn a browser process.

Code Reference

Source Location

Repository: puppeteer
launch function: packages/browsers/src/launch.ts (lines 205-207)
Process class: packages/browsers/src/launch.ts (lines 277-653)
LaunchOptions: packages/browsers/src/launch.ts (lines 135-198)

Signature

function launch(opts: LaunchOptions): Process;

class Process {
  get nodeProcess(): child_process.ChildProcess;
  close(): Promise<void>;
  kill(): void;
  waitForLineOutput(regex: RegExp, timeout?: number): Promise<string>;
}

Import

import {launch} from '@puppeteer/browsers';

I/O Contract

Inputs

Name	Type	Required	Description
opts.executablePath	string	Yes	Path to browser binary
opts.args	string[]	No	CLI arguments for the browser
opts.pipe	boolean	No	Use pipe transport instead of WebSocket
opts.dumpio	boolean	No	Pipe browser stdout/stderr to Node.js process
opts.env	Record<string, string>	No	Environment variables for the browser process
opts.handleSIGINT	boolean	No	Forward SIGINT to browser (default: true)
opts.handleSIGTERM	boolean	No	Forward SIGTERM to browser (default: true)
opts.handleSIGHUP	boolean	No	Forward SIGHUP to browser (default: true)
opts.detached	boolean	No	Detach browser process from parent

Outputs

Name	Type	Description
return	Process	Process wrapper with close(), kill(), waitForLineOutput() methods

Usage Examples

import {launch, install, Browser, detectBrowserPlatform, resolveBuildId} from '@puppeteer/browsers';

// First install the browser
const platform = detectBrowserPlatform();
const buildId = await resolveBuildId(Browser.CHROME, platform, 'stable');
const installed = await install({
  cacheDir: '/tmp/browsers',
  browser: Browser.CHROME,
  buildId,
});

// Then launch it
const process = launch({
  executablePath: installed.executablePath,
  args: ['--remote-debugging-port=9222'],
});

// Wait for WebSocket endpoint
const wsEndpoint = await process.waitForLineOutput(
  /DevTools listening on (ws:\/\/.*)$/,
  30000
);
console.log(`Browser listening at: ${wsEndpoint}`);

// Cleanup
await process.close();

Related Pages

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Principle

Implementation

Heuristic

Environment