Updated: 2020-08-10

I’m working on WebKit on Windows these days. Sometimes I see someone asking about WebKit for Windows. I would summarize the current situation.

AppleWin port

AppleWin port is a upstream port which is used for iTunes for Windows. It uses the same components with Mac port, i.e. Core Graphics and Core Foundation, etc.

It supports only WebKit1. They removed AppleWin WebKit2. And, WebKit thread is not separated from UI thread. The browser becomes unresponsive while running JavaScript benchmarks.

AppleWin port is supporting both 32bit and 64bit versions because iTunes for Windows is supporting them. However, 32bit version of Windows JavaScriptCore is supporting only Low Level Interpreter C Loop, not supporting JIT. LLInt CLoop has the high stack consumption issue for MSVC.

The latest 64bit built binary can be downloaded from Buildbot. You need to install iTunes on your PC by using MSI installer. You can’t use Microsoft Store version of iTunes.

You can compile out both 32bit and 64bit AppleWin port by yourself. However, the required library WebKitSupportLibrary.zip is not redistributable.

WinCairo port

WinCairo port is a redistributable upstream Windows port. It supports both WebKit1 and WebKit2, but it plans to remove WebKit1. WinCairo WebKit1 and WebKit2 are using GraphicsLayerTextureMapper for Accelerated Compositing at the moment, but it’s still immature. I’d like to recommend to disable accelerated compositing by using menu at the moment.

It supports only 64bit. Its JavaScriptCore supports LLInt Asm, baseline JIT and DFG JIT, but neither FTL JIT nor Web Assembly.

The latest built binary can be downloaded from Buildbot.

Microsoft Playwright is distributing WinCairo port WebKit with modifications.

Here is the list of Microsoft Playwright modifications to WinCairo as far as I know.

  • Disabled high DPI support
  • Use the complex text code path
  • No way to disable accelerated compositing

QtWebKit

QtWebKit a downstream port which supports WebKit1 and WebKit2.

In WebKit1, WebKit thread and UI thread are separated. It seems that Accelerated Compositing doesn’t work on Windows.

WebKitGTK

WebKitGTK is a well maintained upstream port, but doesn’t support Windows. So, Cygwin or WSL and X11 server (VcXsrv or Cygwin/X) are needed to run. Cygwin has epiphany and midori packages, but very old.

You can use Microsoft Playwright on WSL.

wget https://playwright.azureedge.net/builds/webkit/1317/webkit-ubuntu-20.04.zip
unzip webkit-ubuntu-20.04.zip
apt-get install libnotify4 libenchant1c2a libgstreamer-plugins-bad1.0-0
./minibrowser-gtk/pw_run.sh https://google.com

See browsers.json and browserFetcher.ts for the URL of the distribution.

Now, WebKitGTK and WPE WebKit have nightly build archives. Bug 215266 – [GTK][WPE] Add a script for generating MiniBrowser bundles

WPE WebKit

WPE WebKit is a well maintained upstream port, but doesn’t support Windows.

JavaFX WebKit

Arunprasad Rajkumar is working on it in June 2019. But I don’t know.

FTW port

FTW port is a new upstream Windows port which uses Direct2D and DirectWrite.

MontionMark 1.1

I found a StackOverflow question of WinCairo performance. Here are the benchmark results on my PC.

Browser MontionMark 1.1
AppleWin r249040 (32bit) AC 8.39
AppleWin r249040 (32bit) non-AC 8.68
WinCairo r249042 (64bit) WK2 non-AC 136.66
WinCairo r249042 (64bit) WK1 AC 68.99
QtWebKit (64bit) WK1 non-AC 115.18
Firefox 68.0.2 (64bit) 272.57
Firefox 68.0.2 (64bit) no-GPU 105.12
  • Windows 10 version 1903 with 150% device scale factor display
  • AppleWin: https://s3-us-west-2.amazonaws.com/archives.webkit.org/win-x86_64-release/249040.zip (This is a 32bit version with regardless to the URL)
  • WinCairo: https://s3-us-west-2.amazonaws.com/archives.webkit.org/wincairo-x86_64-release/249042.zip
  • QtWebKit: otter-browser-win64-1.0.81-weekly272-setup.exe with manually adjusting zooming level

Here are screenshots.