Safari Technology Preview Release 46 is now available for download for macOS Sierra and macOS High Sierra. If you already have Safari Technology Preview installed, you can update from the Mac App Store’s Updates tab. This release covers WebKit revisions 225266-225841. Service Workers Offline applications are important to the web. After HTML5 first tried to accommodate them with the Offline Applica

WebKit contributors have long relied on the WebKit Nightly builds. The WebKit project has been posting these builds since r11994, January 11, 2006. Since their introduction, the nightlies have served a meaningful purpose: “Use the newest untested code in WebKit to find bugs, verify fixes and try the latest features.” Today we’re excited to roll out some improvements to how we deliver WebKit builds

Today we are thrilled to announce WebKit support for WebRTC, available on Safari on macOS High Sierra, iOS 11, and Safari Technology Preview 32. In this post, we will go through an overview of our implementation. We will have future posts that cover more best practices for developers. When talking about WebRTC, we immediately think about making a video conference call. There are two steps to start

Jun 6, 2017 by JF Bastien, Keith Miller, Saam Barati @jfbastien We’re pleased to announce that WebKit has a full WebAssembly implementation. Dynamic Duo WebAssembly is a no-nonsense sidekick to JavaScript. It isn’t meant to be hand-written; rather, it’s a low-level binary format designed to be a suitable compilation target for existing languages such as C++. The WebAssembly code that the browser s

UPDATE (Oct 2018): We’ve renamed our prototype WebGPU proposal to “WebMetal” to avoid confusion with the real WebGPU API. A few weeks ago, we announced the creation of the W3C GPU for the Web Community Group and our proposal, WebGPU. As of Safari Technology Preview Release 26, and WebKit Nightly Build, a WebGPU prototype is available for you to experiment with on macOS. To enable WebGPU, first mak

Apple’s WebKit team today proposed a new Community Group at the W3C to discuss the future of 3D graphics on the Web, and to develop a standard API that exposes modern GPU features including low-level graphics and general purpose computation. W3C Community Groups allow all to freely participate, and we invite browser engineers, GPU hardware vendors, software developers and the Web community to join

As of r209827, 64-bit ARM and x86 WebKit ports use a new garbage collector called Riptide. Riptide reduces worst-case pause times by allowing the app to run concurrently to the collector. This can make a big difference for responsiveness since garbage collection can easily take 10 ms or more, even on fast hardware. Riptide improves WebKit’s performance on the JetStream/splay-latency test by 5x, wh

Creating forms in HTML has always been complicated. You first need to write the correct markup, then you need to make sure each field has a valid value before submitting, and finally you need to inform the user when there is a problem. Thankfully, new features were introduced in HTML5 to make this a lot easier. In particular, the form controls were extended to support constraints, allowing the bro

It’s 2016. URLs have been used for decades now. You would think they would have consistent behavior. You would be wrong. Conformance A quick visit to the URL constructor conformance test shows that modern specification conformance is poor; no shipping browser passes more than about 2/3 of the tests, and more tests are needed to cover more edge cases. WebKit trunk, which is shipped in Safari Techno

Co-written with Said Abou-Hallawa and Simon Fraser Today, we are pleased to introduce MotionMark, a new graphics benchmark for web browsers. We’ve seen the web grow in amazing ways, making it a rich platform capable of running complex web apps, rendering beautiful web pages, and providing user experiences that are fast, responsive, and visibly smooth. With the development and wide adoption of web

When implementing new features for the Web, it’s important for us to be able to get them into the hands of developers early, so they can give new things a try. (Of course, this also helps us identify and fix bugs!) In the past, browsers did this by using vendor-prefixed names for features. This was intended to protect the Web from the churn of spec and implementation changes. Browsers would eventu

As of r195562, WebKit’s FTL JIT (Faster Than Light Just In Time compiler) now uses a new backend on OS X. The Bare Bones Backend, or B3 for short, replaces LLVM as the low-level optimizer in the FTL JIT. While LLVM is an excellent optimizer, it isn’t specifically designed for the optimization challenges of dynamic languages like JavaScript. We felt that we could get a bigger speed-up if we combine

JetStream is the benchmark suite that WebKit developers use to tune JavaScript engine performance. It comprises latency benchmarks, which measure the start-up and worst-case execution times of the JavaScript engine, and throughput benchmarks, which measure average throughput in steady state. We want to make JetStream accurately reflect our performance goals — a change that improves the score shoul

Browser extensions have been a big part of modern browsers for a while now. With extensions, everyone can change their browser to their preferences. Today, there are several models to extend browsers. Most extensions are written in JavaScript and loaded by the browser, following a model introduced by Mozilla over a decade ago. That model is also used with WebKit. It is the classical way to write e

CSS Selector matching is used for Style Resolution and SelectorQuerying. We describe CSS Selector JIT in WebKit, optimizing CSS Selector Matching with …