Principle:Puppeteer Puppeteer Browser Launching
| Knowledge Sources | |
|---|---|
| Domains | Browser_Automation, Testing |
| Last Updated | 2026-02-11 23:00 GMT |
Overview
A mechanism that initializes and connects to a browser process, providing programmatic control over its functionality through a high-level API.
Description
Browser Launching is the foundational step in any browser automation workflow. It involves spawning a new browser process (or connecting to an existing one) and establishing a communication channel between the automation library and the browser engine.
The process involves:
- Resolving which browser binary to execute (Chrome, Firefox, or a custom path)
- Configuring launch arguments (headless mode, viewport size, proxy settings)
- Spawning the browser as a child process
- Establishing a WebSocket connection using either Chrome DevTools Protocol (CDP) or WebDriver BiDi protocol
- Returning a high-level Browser object that serves as the entry point for all subsequent automation
This principle is protocol-agnostic: the same launch interface works regardless of whether the underlying communication uses CDP or WebDriver BiDi.
Usage
Use this principle at the beginning of every browser automation script. Browser launching is required before any page navigation, interaction, or data extraction can occur. Choose between headless mode (for CI/CD pipelines, server-side rendering) and headed mode (for debugging and development).
Theoretical Basis
The browser launching process follows a factory-dispatcher pattern:
# Pseudo-code for browser launch dispatch
1. Receive LaunchOptions from user
2. Determine target browser (chrome | firefox)
3. Select appropriate launcher (ChromeLauncher | FirefoxLauncher)
4. Resolve executable path from cache or configuration
5. Construct browser-specific CLI arguments
6. Spawn browser as child process
7. Wait for WebSocket endpoint (ws://HOST:PORT/devtools/browser/ID)
8. Connect protocol transport (CDP or BiDi)
9. Return Browser instance
The key architectural insight is the separation of the launch interface from the protocol-specific connection logic, enabling cross-browser support through a single API.