Lightpanda

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Introduction

Lightpanda is a headless browser built for machines rather than people. The README is explicit that it is ‘not a Chromium fork’ and ‘not a WebKit patch’ but a new browser written in Zig. It parses HTML with html5ever, runs JavaScript with the V8 engine, implements the DOM and web APIs such as XHR and Fetch, and has no rendering engine for pixels at all.

The point of leaving out rendering is resource use. The project publishes a benchmark of 933 real pages fetched on an AWS EC2 m5.large instance, in which Lightpanda used about 123 MB of peak memory against about 2 GB for headless Chrome, and finished 100 pages in about 5 seconds against 46 seconds. These are the vendor’s own numbers, and real results depend heavily on the sites you load, but the design goal is clear: run many more browser sessions per machine.

Lightpanda speaks the protocols that existing tools already use. It starts a Chrome DevTools Protocol (CDP) server, by default on port 9222, so a Puppeteer or Playwright script can connect to it instead of launching Chrome. It also offers a WebDriver BiDi server, a mode that dumps a page’s DOM or Markdown, a native MCP server for AI agents, and an ‘agent mode’. CodeceptJS ships a helper for it as an alternative browser engine.

For testing, Lightpanda is most useful where you need fast, cheap browser sessions that execute JavaScript but do not need pixels: smoke checks that a single-page app boots and renders the right DOM, link and content checks, crawling for test data, and agent-driven exploratory runs. It is not a replacement for real-browser end-to-end tests where layout, screenshots, fonts or browser-specific behaviour matter, because it does not render and does not match Chrome feature for feature.

The project tracks web-platform coverage openly in its README status list (CORS, cookies, custom headers, proxy support, network interception, form input, click and more). Binaries are available for Linux and macOS through Homebrew, nightly builds, Nix and Docker. Note that by default Lightpanda sends usage telemetry; the README documents setting LIGHTPANDA_DISABLE_TELEMETRY=true to turn it off, which most CI setups should do.

There is also a hosted cloud offer on lightpanda.io where Puppeteer connects over a WebSocket endpoint with a token. In the quality loop, Lightpanda sits at the end-to-end stage as an execution engine underneath your existing automation framework, and is increasingly used as the browser for AI testing agents.

The source code is at lightpanda-io/browser on GitHub under the AGPL-3.0 licence, with about 41,900 stars; the most recent commit was on 11 November 2026.

Features

1. Built from scratch: A new browser engine in Zig with V8 for JavaScript, not a fork of Chromium or WebKit.
2. CDP server: Puppeteer, Playwright and other CDP clients can connect to it as if it were Chrome.
3. WebDriver BiDi: A BiDi server for clients that use the newer WebDriver protocol.
4. Low resource use: Vendor benchmark shows roughly 16x less memory and 9x faster execution than headless Chrome on its test set.
5. DOM and Markdown dump: Fetch a URL and output the processed DOM or Markdown from the command line.
6. Network features: Cookies, custom headers, proxy support and network interception.
7. MCP server: A native MCP server so AI agents can browse through Lightpanda, with session management tools.
8. Agent mode: A mode aimed at AI agents and automation workflows.
9. Robots.txt option: --obey-robots makes crawls respect robots.txt.
10. Cloud option: A hosted service for running sessions without managing binaries.

Pros

1. Cheap parallelism: Many more sessions per machine than headless Chrome for DOM-level checks.
2. Drop-in for CDP scripts: Existing Puppeteer or Playwright code often needs only a connect change.
3. Free to use: Open source under the AGPL-3.0 licence, so the core tool costs nothing to use.
4. Actively maintained: The repository had commits as recent as 11 November 2026.
5. Community: About 41,900 GitHub stars.

Cons

1. No rendering: No screenshots or visual layout, so it cannot replace real-browser visual or layout tests.
2. Web-platform gaps: It is a young engine; some sites and APIs will behave differently from Chrome.
3. AGPL licence: The AGPL-3.0 licence can matter if you modify it and offer it as a network service.
4. Telemetry on by default: Usage telemetry is sent unless you set LIGHTPANDA_DISABLE_TELEMETRY=true.

Usage and Links (Example)

Install and start a CDP server:

brew install lightpanda-io/browser/lightpanda
LIGHTPANDA_DISABLE_TELEMETRY=true lightpanda serve --host 127.0.0.1 --port 9222

Point an existing Puppeteer script at it:

import puppeteer from "puppeteer-core";

const browser = await puppeteer.connect({ browserWSEndpoint: "ws://127.0.0.1:9222" });
const page = await browser.newPage();
await page.goto("https://example.com/");
const title = await page.title();
if (!title.includes("Example")) throw new Error(`Unexpected title: ${title}`);
await browser.close();

Practical tips:

1. Use Lightpanda for fast DOM-level smoke checks and keep a real-browser suite for layout and visual tests.
2. Disable telemetry in CI with the environment variable.
3. Run the same smoke script against Chrome occasionally to catch engine differences.

Resources:

• Lightpanda website
• GitHub repository

Pricing

Lightpanda is free and open source under the AGPL-3.0 licence.

Recommended for?

1. Teams running many DOM-level checks where headless Chrome’s memory cost is the bottleneck.
2. AI testing agents and crawlers that need a fast JavaScript-capable browser.
3. Smoke tests for single-page apps in CI.
4. Not a fit for screenshot, layout or cross-browser compatibility testing.

Conclusion

Lightpanda is one of the most interesting new pieces of browser-automation infrastructure: a purpose-built headless engine that existing CDP tools can drive. Its GitHub popularity (about 41,900 stars) reflects how much demand there is for cheaper headless sessions.

Treat it as a fast execution engine for DOM-level checks and agents, not as a full stand-in for Chrome, Firefox or Safari. Used that way, it can cut the cost of large automated check suites significantly.

On CheckOps, Lightpanda is filed under the End-to-end & functional stage. Related tools listed here include Browserless, Puppeteer, Playwright, chromedp, Rod and Selenium Grid. Before choosing, compare them on licence, supported languages and platforms, hosting model, and how well each fits your existing CI pipeline. Facts on this page were checked against the official website, documentation and repository on 11 November 2026; statements the vendor makes about its own product are marked as vendor claims.