spiral@out:~/blog$ cat transmissions/lightpanda.md

Lightpanda: A Headless Browser That Isn't Chrome

[2026-10-31] ::browser, automation, scraping, zig, tools

Lightpanda is a headless browser built from scratch for automation and AI agents. The README is blunt about what it isn't: "Not a Chromium fork. Not a WebKit patch. A new browser, written in Zig."

It's on GitHub Trending today with about 39,100 stars as of 2026-10-31, and it's licensed under AGPL-3.0.

Why it exists

Plain HTTP requests used to be enough to scrape or test a site. They aren't any more, because most pages build themselves in JavaScript: single-page apps, infinite scroll, instant search. So the usual answer is to run headless Chrome. That works, but Chrome is a desktop browser with the window taken off, and the README's complaint is that it's "heavy on RAM and CPU" and "hard to package, deploy, and maintain at scale" once you're running hundreds of copies.

Lightpanda keeps the parts automation needs and drops the rest. It has no graphical rendering engine at all. The project's own benchmark, which loads 933 real pages on an AWS m5.large, reports peak memory of 123 MB against Chrome's 2 GB for 100 pages, and 5 seconds against 46. That's the source of the "16x lighter and 9x faster" headline. These are the project's numbers on its own test, so treat them as a direction rather than a promise for your workload.

How it works

The browser is assembled from proven parts with new glue in Zig: V8 runs the JavaScript, libcurl does the networking, and Servo's html5ever parses HTML. Lightpanda supplies the DOM, the web APIs and the servers that let other tools drive it. The status list covers what you'd expect for automation:

  • DOM APIs, XHR and Fetch, CORS and cookies
  • Clicks and form input
  • Custom headers, proxies and network interception
  • An ad blocker, and robots.txt support with --obey-robots
  • The Chrome DevTools Protocol (CDP) and WebDriver BiDi

CDP is the important one. It's what Puppeteer and Playwright speak, so existing scripts can switch to Lightpanda by changing one line: the endpoint they connect to. Progress against the standard Web Platform Tests is published daily.

There's also an AI side. lightpanda agent drives the browser from plain-English tasks using Anthropic, OpenAI, Gemini, Mistral, OpenRouter or a local model through Ollama or llama.cpp. The useful twist is what it leaves behind. A session can be saved as a "PandaScript," which is ordinary JavaScript plus a few browser primitives, and replayed with lightpanda run with no model involved. You prototype with an LLM and run the deterministic script in production. There's a built-in MCP server too, over stdio or over HTTP with a separate browsing session for each agent.

Trying it

On Linux, grab the nightly binary and check it:

curl -L -o lightpanda https://github.com/lightpanda-io/browser/releases/download/nightly/lightpanda-x86_64-linux && \
chmod a+x ./lightpanda
./lightpanda version

It's also in Homebrew (brew install lightpanda-io/browser/lightpanda), the AUR and a Nix flake, and there's a Docker image:

docker run -d --name lightpanda -p 127.0.0.1:9222:9222 lightpanda/browser:latest

The quickest test is to fetch a page and dump it. --dump markdown converts the rendered page to Markdown, which is handy for feeding text to an LLM:

./lightpanda fetch --obey-robots --dump html https://demo-browser.lightpanda.io/campfire-commerce/

For Puppeteer or Playwright, start the CDP server and point your script's browserWSEndpoint at ws://127.0.0.1:9222:

./lightpanda serve --obey-robots --host 127.0.0.1 --port 9222

The fine print

  • Telemetry is on by default. Set LIGHTPANDA_DISABLE_TELEMETRY=true to turn it off. It's in the README, but it's easy to miss.
  • It isn't Chrome. A new engine means sites that work in Chrome won't all work here yet. Check the Web Platform Tests results, and test your target sites before you move a pipeline over.
  • No pixels. With no rendering engine, it can't stand in for visual testing or real screenshots.
  • Platform gaps. There's no native Windows build (use WSL) and none for Android. The Linux binaries need glibc, so they won't run on Alpine or other musl images.
  • Nightlies. The install docs point at nightly builds, so expect the occasional rough edge.
  • AGPL, plus a CLA. If you offer a modified Lightpanda as a network service, you have to share your changes. Contributors also have to sign a CLA.

Who it's for

Lightpanda is for anyone running a lot of headless browsers: scrapers, crawlers, AI agents that browse, and test suites that only need the DOM. If you're paying for Chrome's memory at scale, it's worth an afternoon. If you need pixel-perfect rendering or every last corner of the web platform, stay with Chrome for now and keep an eye on the test results.

The GitHub repo and the documentation are the places to start, and it's in the resource index now.

End of transmission.

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