Apple Releases Safari Technology Preview 187 With Bug Fixes and Performance Improvements - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Releases Safari Technology Preview 187 With Bug Fixes and Performance Improvements

Apple today released a new update for Safari Technology Preview, the experimental browser Apple first introduced in March 2016. Apple designed the ‌Safari Technology Preview‌ to test features that may be introduced into future release versions of Safari.

Safari Technology Preview Feature
‌Safari Technology Preview‌ 187 includes fixes and updates for Accessibility, Animations, CSS, Forms, Rendering, Scrolling, Storage, SVG, Web API, and WebGL.

The current ‌Safari Technology Preview‌ release is compatible with machines running macOS Ventura and macOS Sonoma, the latest version of macOS that Apple released in September 2023.

The ‌Safari Technology Preview‌ update is available through the Software Update mechanism in System Preferences or System Settings 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.

Popular Stories

iOS 27 Next to iPhone

Here's When iOS 27 Rolls Out Today in Every Time Zone [Update: It's Out]

Sunday September 13, 2026 3:00 am PDT by
Update 10:04 a.m.: iOS 27 is rolling out now, though it may take a bit for all users to see it, so keep checking! Apple is about to release iOS 27, which will finally deliver more advanced Siri AI capabilities as well as a variety of other refinements, improvements, and new features to iPhones. It's Apple's biggest software update of the year, and Apple announced at Wednesday's iPhone event...
iOS 27 Icon iPhone

iOS 27 Available Now With These 8 New Features

Monday September 14, 2026 9:00 am PDT by
Update — 10 a.m. Pacific Time: Apple has released iOS 27. During its iPhone 18 Pro and iPhone Duo event last week, Apple announced that iOS 27 will be released widely on Monday, September 14. iOS 27 should be available around 10 a.m. Pacific Time / 1 p.m. Eastern Time today via the Settings app, under General → Software Update. Below, we have highlighted eight new features and...
deep black iphone 18 pro

Apple Says iPhone 18 Pro Max Sold in U.S. Differs in One Way

Saturday September 12, 2026 3:27 pm PDT by
As noted by Nicolas Lellouche, who writes for the French tech website Numerama, Apple has updated its tech specs pages for the iPhone 18 Pro and iPhone 18 Pro Max to clarify which models are equipped with its new C2 cellular modem and where. Apple now says the iPhone 18 Pro has a C2 modem worldwide, while the iPhone 18 Pro Max uses the chip in every country except for the U.S. According...

Top Rated Comments

christarp Avatar
35 months ago
Damn, I can't believe it, they've done it again! They've released a new Safari Technology Preview With Bug Fixes and Performance Improvements!
Score: 8 Votes (Like | Disagree)
Diopter Avatar
35 months ago

Do you really observe (performance) improvements over regular version? 🤨
I think you’re missing the point of Safari Technology Preview, and Xeenon didn’t claim it had better performance compared to Safari. It isn’t guaranteed to be faster overall, or even stable, but specific things might be.

It’s a testing ground for technologies that might eventually make their way into the release version of Safari. Web developers can test the latest WebKit version, report bugs, test experimental and developing standards, etc. It isn’t a straight “beta of the next Safari”.

But it often does include performance improvements for specific things, which will eventually make it into Safari (for example, a couple of years ago I identified a performance regression in certain types of MP4 files played in Safari and this was reported and fixed in Safari Technology Preview, and the fix was in the next public Safari release). It also often includes new bugs, because it’s an in-progress build with web technologies that may not even have a finalised standard yet (a recent example being CSS nesting, which went through several iterations).

So non-developers probably shouldn’t be using Safari Technology Preview.
Score: 2 Votes (Like | Disagree)
35 months ago
It would be helpful if they would specify which bugs are being fixed, and under which situations performance is being improved. Whatever happened to proper release notes?
Score: 2 Votes (Like | Disagree)
Diopter Avatar
35 months ago

Whatever happened to proper release notes?
MacRumors might pump out the same post every time there's a new STP release (which, by the way, is roughly every two weeks!), but Apple releases very detailed release notes, as noted by xeenon above.

In fact the release notes for Safari and Safari Technology Preview over the past few years have become increasingly detailed. It's not uncommon for Apple/WebKit to also do a deep dive on the specific changes and features for Safari point releases, including explanations of changes and code examples. For example, this one last month:

https://webkit.org/blog/14787/webkit-features-in-safari-17-2/

I highly recommend following the WebKit RSS feed: https://webkit.org/feed/

You'll get a lot more out of it than you will from MacRumors' generic filler posts.
Score: 1 Votes (Like | Disagree)
35 months ago

It would be helpful if they would specify which bugs are being fixed, and under which situations performance is being improved. Whatever happened to proper release notes?
There are very detailed release notes (down to the WebKit GitHub link and radar number!) for every Safari Technology Preview release. https://developer.apple.com/documentation/safari-technology-preview-release-notes/stp-release-187
Score: 1 Votes (Like | Disagree)
carrrrrlos Avatar
35 months ago
Would be great if Apple looked in the rear view on occasion. There is no support for Safari on OS 10.11 for my 2009 iMac (yeah, still kinda running w/ the OG GPU). Firefox is great for streaming Netflix though.
Score: 1 Votes (Like | Disagree)

🔗 Related Apple News & Rumors

Stay updated with the latest Apple ecosystem news and verified rumors