Changelog and versions

Lightningpanda ships as one npm package, @povio/lightning-panda, that holds the SDK, the lightningpanda CLI and the native browsers. Every release is cut from a Git tag; this page lists the channels, the platforms, how to pin a version and what changed in recent releases.

Package

npm name	@povio/lightning-panda
License	AGPL-3.0-only
Binary	lightningpanda (node_modules/.bin/lightningpanda)
Entry points	@povio/lightning-panda (SDK), @povio/lightning-panda/e2e (suite runner API), @povio/lightning-panda/playwright and @povio/lightning-panda/test (Playwright drop-in)
Install scripts	None. The browsers are inside the tarball; nothing is downloaded at install time.

Check what you have installed:

bunx lightningpanda version
# lightningpanda 0.0.33
# engine: JavaScriptCore; capabilities: Capabilities { ..., fork: true, ... }

fork: true means the browser was built against the patched JavaScriptCore and supports fork mode.

Release channels

npm dist-tag	Git tag	What it holds
latest	vX.Y.Z	Stable releases. bun add @povio/lightning-panda installs this.
next	vX.Y.Z-rc.N or vX.Y.Z-rc	Release candidates. Publishing a stable version does not move next; it keeps pointing at the last RC.

As of 2026-11-12, latest is 0.0.33 and next is 0.0.17-rc.1 (an old candidate, older than latest). Use next only when a release candidate is announced.

bun add @povio/lightning-panda          # latest
bun add @povio/lightning-panda@next     # newest release candidate
npm view @povio/lightning-panda dist-tags

Platforms and runtimes

Platform	Browser in the package	Fork mode
macOS 14+ arm64 (Apple silicon)	native/darwin-arm64, patched JavaScriptCore	Yes
macOS 14+ x64 (Intel)	native/darwin-x64, system JavaScriptCore	No
Linux x64, glibc 2.39+ (Ubuntu 24.04, Debian 13, Fedora 40 or newer)	native/linux-x64, patched JavaScriptCore, ICU bundled in lib/	Yes
Linux arm64, glibc 2.39+	native/linux-arm64, patched JavaScriptCore, ICU bundled in lib/	Yes

Linux builds ship since v0.0.27 (on npm since 0.0.28). Release Linux binaries have no source-line debug information. The Intel macOS binary is checked in CI but not executed there.

On any other OS, or to use a browser you built yourself, use Lightningpanda.connect() against a remote lightningpanda serve, or set LIGHTNINGPANDA_BIN. The package has no os restriction, so it installs everywhere.

Runtime	Supported
Node.js	22 or newer (engines.node: ">=22")
Bun	Supported. Release CI tests the packed tarball with Bun 1.4.0; no minimum is declared.

Pinning a version

Versions are immutable on npm. Pin the exact version so a CI run and a laptop run the same browser:

bun add --exact @povio/lightning-panda@0.0.33

{
  "devDependencies": {
    "@povio/lightning-panda": "0.0.33"
  }
}

The browser binary is part of the package, so pinning the package pins the browser. lightningpanda version prints the version the binary was built as; CI checks that it matches the tag.

Versions are 0.0.x: any release may change behaviour. Read the notes below before upgrading.

Release notes

Each tag vX.Y.Z creates a GitHub release named "Rust Lightpanda vX.Y.Z" in povio/lightningpanda, with generated notes (the merged pull requests) and these assets:

Asset	Contents
lightningpanda-rust-vX.Y.Z-macos-arm64.tar.gz	Browser on system JavaScriptCore, lp-snapshot-compare, the client
lightningpanda-rust-vX.Y.Z-macos-x64.tar.gz	Same, Intel
lightningpanda-rust-vX.Y.Z-macos-arm64-fork.tar.gz	Browser with the patched JavaScriptCore (fork mode)
lightningpanda-rust-vX.Y.Z-linux-x64.tar.gz, ...-linux-arm64.tar.gz	Linux browsers, ICU in lib/
povio-lightning-panda-X.Y.Z.tgz	The npm package
lightningpanda-jsc-source-vX.Y.Z.tar.gz	The patched JavaScriptCore source (LGPL)
SHA256SUMS.txt	Checksums of the assets

The repository is private at the time of writing, so the GitHub releases need repository access. The npm package is public.

A new version can take a while to appear on npm after its release: npm has listed versions up to about an hour after publication. If bun add @povio/lightning-panda@X.Y.Z cannot find a fresh version, wait and retry.

Unreleased (main)

On main after v0.0.33:

• Faster connection start and fork mode (#303): no JavaScript realm is created before a connection's first command; the fork template is forked from the server process.
• Engine reuse across connections (#304): connections reuse the engine; the patched JavaScriptCore is linked statically (the arm64 macOS package no longer carries a lib/ directory beside the browser); memory is returned after pages close.
• Vendored engines updated (#302): Blitz, Taffy and Stylo 0.24.0.

Version history

0.0.33 (2026-11-11)

• Fork mode: the root template compiles the app's ES modules once; forked pages load them without parsing (#301).
• Fork mode: the fork holds JavaScriptCore's timer thread and each forked child arms its own watchdog timer (#300).

0.0.32 (2026-11-11)

• New serve --hyphen-digit-breaks (LIGHTNINGPANDA_HYPHEN_DIGIT_BREAKS): Chrome's line break between a hyphen and a digit (#299).

0.0.31 (2026-11-10)

• PDF: variable fonts print at the weight and optical size they were shaped at (#294).
• PDF: glyphs substituted by OpenType features extract as their source text on page-box PDFs (#292).
• Fonts: @font-face unicode-range decides which face draws a character (#293).
• XML documents stop at each script (#296).
• WPT coverage gate on every pull request (#276, #295).

0.0.30 (2026-11-10)

• New lightningpanda e2e suite runner: one process, one browser per suite (#289). See the runner guide.
• Shared profiles across clients of one serve --fork, serve lifetime fixes (#289).
• Fork mode: less CPU per forked page (fast exit, 32 MB JIT pool, JavaScriptCore heap growth) (#291).

0.0.29 (2026-11-10)

• Doubles cross CDP unchanged (float round-trip) (#290).

0.0.28 (2026-11-10)

• First npm release with the Linux browsers (smaller Linux payload).
• Fixed viewport invalidation on unstyled nodes.

0.0.27 (2026-11-10)

• Linux x64 and arm64 builds, in CI and in the GitHub release (#288). Not published to npm.

0.0.26 (2026-11-09)

• Module fetches are shared; service worker request ownership is preserved.

0.0.25 (2026-11-09)

• Fork IPC survives interrupted system calls.

0.0.24 (2026-11-09)

• A click's stability frames no longer wait an extra turn each (#287).

0.0.23 (2026-11-09)

• Bursts of cached resources no longer close CDP connections.

0.0.22 (2026-11-08)

• Playwright suites run on Lightningpanda by swapping the import (#278). See Coming from Playwright.
• Web-platform gaps found by the WPT survey filled.
• PDF pagination at Chrome's speed (#282); incremental tables and upstream Blitz/Taffy/Stylo (#279); whole-program performance passes (#283-#286).

Earlier releases

Version	Date	Notes
0.0.21	2026-11-06	DOM, binding, CDP and style data maintained at mutation time (#274); deferred screenshot state preserved, passwords masked (#272)
0.0.20	2026-11-05	Release CI fix
0.0.19	2026-11-05	The npm package ships the fork-capable arm64 browser (#271); GitHub release assets built from the tag (#270). npm only, no GitHub release.
0.0.18	2026-11-05	DOM calls through the JITs, lazy startup (#268); WPT parity on the bench subset (#269); table layout fixes
0.0.17	2026-11-02	First npm release (published 2026-11-04)
0.0.17-rc.1	2026-11-04	Tag-based npm publishing; the current next
0.0.1 to 0.0.16	2026-10-20 to 2026-11-02	GitHub releases only