lightpanda

Headless browser designed for AI and automation

TLDR

Fetch a URL and dump the rendered HTML to stdout

$ lightpanda fetch --dump html [url]

Fetch a URL and output as markdown

$ lightpanda fetch --dump markdown [url]

Start a CDP server on the default host and port

$ lightpanda serve

Start a CDP server on a specific host and port

$ lightpanda serve --host [127.0.0.1] --port [9222]

Fetch a URL while obeying robots.txt

$ lightpanda fetch --obey_robots --dump html [url]

Fetch a URL through an HTTP proxy

$ lightpanda fetch --http_proxy [proxy_host:port] --dump html [url]

SYNOPSIS

lightpanda command [options] [url]

Lightpanda is an open-source headless browser built from scratch in Zig with the V8 JavaScript engine, purpose-built for AI agents, web scraping, LLM training, and test automation. Unlike headless modes of traditional browsers, Lightpanda skips graphical rendering entirely, focusing only on DOM construction and JavaScript execution.
It exposes a Chrome DevTools Protocol (CDP) endpoint, making it compatible with existing automation tools like Playwright, Puppeteer, and chromedp as a drop-in replacement for headless Chrome. The fetch command retrieves a single URL and dumps the rendered page, while serve launches a persistent CDP server for remote browser control.
Lightpanda achieves 9x less memory usage and 11x faster execution compared to headless Chrome, making it particularly suited for high-volume scraping and automation workloads.

PARAMETERS

fetch

Fetch a URL, execute JavaScript, and output the rendered page content to stdout.

serve

Start a Chrome DevTools Protocol (CDP) server for remote automation via Playwright, Puppeteer, or raw CDP clients.

help

Display available commands and options.

--dump html|markdown

Output format for the fetched page. Use html for rendered HTML or markdown for a Markdown conversion. (fetch only)

--with_base

Add a \<base\> tag in the dumped output. (fetch only)

--host address

Host address for the CDP server. Default 127.0.0.1. (serve only)

--port port

Port for the CDP server. Default 9222. (serve only)

--timeout seconds

Inactivity timeout in seconds before disconnecting clients. Default 10. (serve only)

--obey_robots

Fetch and obey the robots.txt of the target web pages.

--http_proxy host:port

HTTP proxy to use for all requests. Supports optional username:password for basic authentication.

--http_timeout milliseconds

Maximum time in milliseconds the transfer is allowed to complete. 0 means no timeout. Default 10000.

--log_level level

Set logging verbosity. Default info. Use debug for detailed output.

--log_format format

Set log output format. Use pretty for human-readable output.

CAVEATS

Lightpanda is in beta and does not yet implement the full web platform. Complex web applications that rely on advanced CSS layout, canvas, WebGL, or certain newer Web APIs may not work correctly. Windows is not natively supported; use WSL instead. As a non-Chromium browser, some sites with browser fingerprinting may behave differently.

HISTORY

Lightpanda was created by Francis and Pierre, who previously worked on large-scale web scraping using headless Chrome and found it too resource-heavy for high-volume workloads. They spent over two years building a headless browser from scratch in Zig, choosing the language for its low-level control and performance characteristics. The project was publicly announced on Hacker News in early 2025 and released as open source under the AGPL-3.0 license.