PyroThe headless browser built for tests

A Rust browser on JavaScriptCore. Run your Playwright suite unchanged, write E2E tests that finish in milliseconds, or drive signed-in scrapers from stored profiles.

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Coming from Playwright

Fastest E2E tests

Scraping

🔁

Playwright, unchanged

Swap the import of playwright or @playwright/test for @povio/lightning-panda/playwright. Your tests, config, fixtures and expect calls keep working, and Playwright itself is no longer a dependency.

Migrate a suite

⚡

One command per test

The native driver sends a whole scenario as one LP.run command. Locating, acting, waiting and checking happen inside the browser, so a test is one round trip.

Why a native driver

🧊

Pages booted before the test

Profiles keep signed-in pages loaded ahead of time. In fork mode every test gets a copy-on-write fork of a page that booted once, in about 20 ms.

Fork mode

🗂️

Stored profiles for scrapers

Save cookies and localStorage per identity, give each its own proxy and user agent, and reuse them across runs and processes.

Stored profiles

🖼️

Screenshots and PDFs in the browser

Pages render on the CPU with Blitz, Stylo and Vello. Visual baselines compare inside the browser; Page.printToPDF writes tagged text you can extract.

Rendering

📦

One npm package

@povio/lightning-panda ships the browser for macOS (Apple silicon, Intel) and Linux (x64, arm64) with the CLI and typed APIs. No downloads at install time.

Install

Measured on a real app suite

Test style	Per test	Against
Native `page.run([...])` on a pre-booted page	~3 ms	~34 ms in Playwright
Playwright code through `@povio/lightning-panda/playwright`	14.7 ms	41–44 ms for stock Playwright on the same browser
A fresh fork-mode connection with the app already booted	~20 ms	however long your app takes to boot

Numbers come from the TOS "close a position" flow in this repository's benchmarks (median of 40 runs, fresh page per test). See Performance for the method and for what makes your own suite faster.

bun add --dev @povio/lightning-panda      # or: npm install --save-dev @povio/lightning-panda
bunx lightningpanda serve --port 9222    # a CDP server any client can connect to