Apple launches Safari Technology Preview, a new browser aimed at web developers

Apple today announced it’s expanding its efforts in the area of web development, with the launch of a new version of its Safari web browser, designed specifically for developers. Called Safari Technology Preview, the company says this browser will allow developers to get an early look at upcoming web technologies in OS X and iOS, including things like the latest layout technologies, visual effects, and other developer tools.

The idea is to allow developers to more easily get their hands on these technologies and be able to experiment, then offer feedback to Apple earlier on so the company can make the necessary improvements.

Of course, Apple has for a long time offered Nightly builds of WebKit, the open source browser engine that today runs on hundreds of millions of devices and powers Apple’s Safari. However, getting access to these builds takes a bit more effort than using the new Safari Technology Preview browser. Instead, with the new browser, its updates are distributed every two weeks by way of the Mac App Store’s software update mechanism. That means it’s less hassle to run a browser that features the latest advances in web technologies, including HTML, JavaScript, CSS and WebKit.

Plus, the browser allows developers to access the latest versions of Web Inspector and Responsive Design Mode – the latter which is used to help developers build websites that work across devices, from desktop to mobile.

Other advantages this version of Safari offers over using a Nightly build is that it’s signed and validated by Apple, and it works with iCloud. The lack of iCloud support, in fact, has been a pain point for web developers who wanted to use a Nightly build as their primary browser. Now, they’ll have a different option, while still being able to use their bookmarks, access their Reading List and access the tabs they’ve opened on other devices.

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In addition, Safari Technology Preview is a standalone application, meaning it can run side-by-side with the shipping version of Safari, to make it easy to switch between the two builds. (The Technology Preview version will feature a purple icon to differentiate it from the shipping version.)

While the big news is the product’s actual launch, developers will also likely be interested to learn what’s shipping in the debut version, out today. This includes a variety of first-release features, such as:

  • ECMAScript 6: Apple says this is one of the most complete implementations of ECMAScript 6 (ES6), the latest version of JavaScript. ES6 offers support for classes that allow developers to use the object-oriented principles in their JavaScript code, iterators, and new APIs.
  • B3 JIT JavaScript Compiler: B3 is a new low-latency, compiler designed from the ground up for JavaScript. B3 optimizes for speedy initial compile times while optimizing the compiled JavaScript for sustained performance.
  • Updated IndexedDB Implementation: IndexedDB lets developers store lots of structured data on the client and access that data quickly. Developers have asked for an improved implementation, so Apple released this revamped IndexedDB implementation that is more stable and more standards compliant.
  • Shadow DOM: Shadow DOM makes it easier to build large-scale web applications by allowing developers to expose elements on a webpage and defining how they interact with their application. WebKit is the first browser engine to implement this latest version.
  • Support for programmatic cut and copy to the clipboard and Content Security Policy Level 2.

While Safari Technology Preview is obviously aimed at developers, it will be accessible to anyone who wants to try it – you won’t need to have a registered Apple Developer account to download the browser.

For tech enthusiasts, there are still some advantages to running this version of Safari, even if you aren’t a web developer. Because the browser offers the latest web technologies, there are real consumer benefits that you can see and feel as you use the web – like better performance and a richer web experience, for example.

Safari Technology Preview is available today, as of 10 AM PT on