Apple Looking to Boost Safari JavaScript Performance with New Accelerator Upgrades

Monday May 12, 2014 8:36 am PDT by Eric Slivka

webkit_logo Apple is apparently working on significant improvements to JavaScript performance for its Safari browser, as shown by the inclusion of accelerator upgrades in recent builds of WebKit, reports InfoWorld.

WebKit is the open source browser engine created by Apple and which serves as the basis for Safari, and the new upgrades to WebKit's "Nitro" JavaScript engine are known as "FTLJIT". With the upgrades, WebKit's JavaScript engine would become more competitive with Google's V8 and Mozilla's SpiderMonkey engines.

FTLJIT is still considered experimental, so although it's being made available in the OS X port of WebKit by default, it's not actually turned on yet -- it has to be enabled through command-line flags.

One attribute that could make FTLJIT stand out from the pack all the more is how well it runs JavaScript code that is not specifically optimized for [Mozilla's] asm.js. Every JavaScript engine will run asm.js code, but only Mozilla's SpiderMonkey honors asm.js-specific optimizations, and right now no other browser maker has elected to follow Mozilla's lead.

The report notes that speed tests are showing WebKit with FTLJIT enabled outperforming Chrome, while Firefox still tops the charts when using asm.js-optimized benchmark tests.

JavaScript has been a key technology for web browsers for many years, facilitating a variety of user interactions with web pages such as dynamic loading of content without reloading pages and handling page animations and other media. Because JavaScript code embedded on a website is run inside the user's browser when the page is loaded, the efficiency of the browser's JavaScript engine can have a significant impact on the user experience as JavaScript implementations become increasingly complex.

It is unclear whether Apple is targeting OS X 10.10 for these JavaScript improvements, but with them only being enabled in the OS X version of WebKit, it appears that there is still substantial work to be done.

Popular Stories

Crackgate? iPhone Duo Owners Report Screens Breaking Along the Hinge

Friday October 23, 2026 11:05 am PDT by Juli Clover

Some iPhone Duos are already experiencing hinge issues that cause display cracks, based on photos shared on Reddit and the MacRumors forums. Almost all of the display faults are right along the hinge, and most result in a line of bright pixels across one side of the screen. An iPhone Duo owner in Australia said his device cracked after being opened fewer than 20 times, and there was no...

• 650 comments

Apple Music Has a Hidden iPod You Can Play With

Friday October 23, 2026 7:11 am PDT by Joe Rossignol

Apple Music has a 404 page easter egg on the web: a functional iPod that appears when you load a page that does not exist, such as music.apple.com/macrumors. "Page Not Found," says Apple. "Give this a spin instead." Apple is clever with this. If you navigate to music.apple.com/ipod instead, the page says "Looking for something?" instead of "Page Not Found." The easter egg is only...

• 82 comments

iPhone Duo Fails JerryRigEverything's Dusty Durability Test

Saturday October 24, 2026 11:27 am PDT by Tim Hardwick

Apple's iPhone Duo has failed JerryRigEverything's latest durability test. Despite its IP68 dust-resistance rating, dust entered the hinge through several ingress points, overwhelming the magnets that hold the phone shut. The bend test then left a permanent green line across the inner display, before the screen became unresponsive. The outer screen with Ceramic Shield 2 scratched at level 7...

• 203 comments