Apple today released a new update for Safari Technology Preview, the experimental browser Apple first introduced one year ago in March of 2016. Apple designed the Safari Technology Preview to test features that may be introduced into future release versions of Safari.
Safari Technology Preview release 28 includes fixes and improvements for CSS, JavaScript, Web API, Web Inspector, WebDriver, Accessibility, Media, Rendering, WebCrypto, Security, and AppleScript. Today's update also includes several tweaks to improve power and performance:
- Changed to pause silent WebAudio rendering in background tabs
- Changed to pause animated SVG images on pages loaded in the background
- Changed to make inaudible background tabs become eligible for memory kill after 8 minutes
- Changed to kill any WebContent process using over 16 GB of memory
- DOM Timers are now throttled to 30fps and aligned in cross-origin iframes
- requestAnimationFrame callbacks are now throttled to 30fps and aligned in cross-origin iframes
The Safari Technology Preview update is available through the Software Update mechanism in the Mac App Store to anyone who has downloaded the browser. Full release notes for the update are available on the Safari Technology Preview website.
Apple's aim with Safari Technology Preview is to gather feedback from developers and users on its browser development process. Safari Technology Preview can run side-by-side with the existing Safari browser and while designed for developers, it does not require a developer account to download.
Top Rated Comments
I'd like to see a per-tab switch in the toolbar (it could be optional and disabled by default) that controls javascript execution for that tab - if the switch is set to off, javascript is paused for that tab. Have an option so that un-visited tabs (opened in the background, when the browser is restarted) can be defaulted to off, so nothing spins up until I bring that tab front-and-center. The number of tabs that I want running javascript while I'm not actively looking at them is vanishingly small, and I can go click the checkbox on those manually.
Also, animated gifs in Safari seem to hit the CPU absurdly hard (adafruit.com, a maker and seller of all sorts of cool electronic parts and kits, seems especially fond of using animated gifs, and if I command-click a dozen or so interesting links into the background, it spins up my MBP's fans to no useful end) - if the image isn't visible on my screen, it shouldn't get any cpu time.