Apple Releases Safari Technology Preview 121 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 release 121 includes bug fixes and performance improvements for Web Inspector, CSS, GPU Process, Media, Web API, JavaScript, WebAssembly, Accessibility, and Speech Recognition.

The current ‌Safari Technology Preview‌ release is the built on the new Safari 14 update included in macOS Big Sur with support for Safari Web Extensions imported from other browsers, tab previews, password breach notifications, web authentication with Touch ID, and more.

The new ‌Safari Technology Preview‌ update is available for both macOS Catalina and macOS Big Sur, the newest version of the Mac operating system.

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

M5 MacBook Pro

Apple Announces New 14-Inch MacBook Pro With M5 Chip

Wednesday October 15, 2025 6:07 am PDT by
Apple today updated the 14-inch MacBook Pro base model with its new M5 chip, which is also available in updated iPad Pro and Vision Pro models. In addition, the base 14-inch MacBook Pro can now be configured with up to 4TB of storage on Apple's online store, whereas the previous model maxed out at 2TB. However, the maximum amount of unified RAM available for this model remains 32GB. Like...
Apple iPad Pro hero M5

Apple Debuts New iPad Pro With M5 Chip, Faster Charging, and More

Wednesday October 15, 2025 6:16 am PDT by
Apple today announced the next-generation iPad Pro, featuring the custom-designed M5, C1X, and N1 chips. The M5 chip has up to a 10-core CPU, with four performance cores and six efficiency cores. It features a next-generation GPU with Neural Accelerator in each core, allowing the new iPad Pro to deliver up to 3.5x the AI performance than the previous model, and a third-generation ray-tracing ...
apple oct 2024 mac tease

Apple Expected to Announce These Two to Three Products 'This Week'

Sunday October 12, 2025 7:05 am PDT by
Apple plans to announce new products "this week," according to Bloomberg's Mark Gurman. Apple's "Mac Your Calendars" teaser last October In his Power On newsletter today, Gurman said the products set to be updated this week include the iPad Pro, Vision Pro, and "likely" the base 14-inch MacBook Pro, with all three likely to receive a spec bump with Apple's next-generation M5 chip. Gurman...
maxresdefault

Here's Everything Apple Announced Today

Wednesday October 15, 2025 3:54 pm PDT by
We didn't get a second fall event this year, but Apple did unveil updated products with a series of press releases that went out today. The M5 chip made an appearance in new MacBook Pro, Vision Pro, and iPad Pro models. Subscribe to the MacRumors YouTube channel for more videos. We've rounded up our coverage and highlighted the main feature changes for each device below. MacBook Pro M5...
joz macbook tease

Apple Teases Upcoming M5 MacBook Pro Launch: 'Something Powerful is Coming'

Tuesday October 14, 2025 11:59 am PDT by
Apple marketing chief Greg Joswiak today teased the launch of an upcoming product, saying "something powerful is coming" on social media. Subscribe to the MacRumors YouTube channel for more videos. A short animation accompanying Joswiak's teaser reveals a brief glimpse of a MacBook Pro along with the words "coming soon." The shape of the MacBook Pro is a V, which is the Roman numeral...
airpods max 2024 colors

AirPods Max 2: Everything We Know So Far

Tuesday October 14, 2025 8:43 am PDT by
Apple's AirPods Max have now been available for almost five years, so what do we know about the second-generation version? According to Apple supply chain analyst Ming-Chi Kuo, the new AirPods Max will be lighter than the current ones, but exactly how much is as yet known. The current AirPods Max weigh 0.85 pounds (386.2 grams), excluding the charging case, making it one of the heavier...
HomePod mini and Apple TV

Apple's Next Rumored Products: New HomePod Mini, Apple TV, and More

Thursday October 16, 2025 9:13 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro, iPad Pro, and Vision Pro with its next-generation M5 chip, but previous rumors have indicated that the company still plans to announce at least a few additional products before the end of the year. The following Apple products have at one point been rumored to be updated in 2025, although it is unclear if the timeframe for any of them has...
Vision Pro M5 Announcement

Apple Updates Vision Pro With M5 Chip, Dual Knit Band, and 120Hz Support

Wednesday October 15, 2025 6:14 am PDT by
Apple today updated the Vision Pro headset with its next-generation M5 chip for faster performance, and a more comfortable Dual Knit Band. The M5 chip has a 10-core CPU, a 10-core GPU with Neural Accelerators, and a 16-core Neural Engine, and we have confirmed the Vision Pro still has 16GB of RAM. With the M5 chip, the Vision Pro offers faster performance and longer battery life compared...
macbook pro blue

Apple's M5 MacBook Pro Imminent: What to Expect

Tuesday October 14, 2025 4:35 pm PDT by
Apple is going to launch a new version of the MacBook Pro as soon as tomorrow, so we thought we'd go over what to expect from Apple's upcoming Mac. M5 Chip The MacBook Pro will be one of the first new devices to use the next-generation M5 chip, which will replace the M4 chip. The M5 is built on TSMC's more advanced 3-nanometer process, and it will bring speed and efficiency improvements. ...
MacBook Pro M5 Screen

New MacBook Pro Does Not Include a Charger in the Box in Europe

Wednesday October 15, 2025 6:59 am PDT by
The new 14-inch MacBook Pro with an M5 chip does not include a charger in the box in European countries, including the U.K., Ireland, Germany, Italy, France, Spain, the Netherlands, Norway, and others, according to Apple's online store. In the U.S. and all other countries outside of Europe, the new MacBook Pro comes with Apple's 70W USB-C Power Adapter, but European customers miss out....

Top Rated Comments

aesc80 Avatar
61 months ago
Posting in here so Safari Beta feels appreciated.
Score: 5 Votes (Like | Disagree)
Kobayagi Avatar
61 months ago
I've been using Safari for more than 10 years, but the latest version is horrible honestly.
It has become very, very slow while I haven't changed anything about my setup or the way I use Safari. I also haven't added any new extensions. Same Mac, same everything. It also runs like crap even without any extensions, clear cookies, cache etc.

Web pages just keep freezing and make me wait for more than 10 sec for them to respond, double taps to zoom with the Magic Mouse make it freak out and lag so much. It makes my MacBook Pro freak out and the temps go high and so does the fanspeed...

I still use Safari because it's convenient with all the iCloud sharing between my iPhone and iPad. I hate to say it, but Chrome runs so, so much better, regardless what Apple's fancy speed bragging comparisons say. But I also don't wanna switch with everything to Google for obvious reasons.
Score: 4 Votes (Like | Disagree)
Rob_2811 Avatar
61 months ago

Hello, Facebook! ;)

Joke aside, what makes you say so? What kind of requirements do you have for Safari to have disappointed you? Genuinely curious.
I just experience a lot of slow loading pages and hangs. Almost every time I can drop the URL in to Firefox and the page loads instantly.

I mostly used Firefox anyway for the superior dev tools but would occasionally use Safari when on the go for the better battery life, I gave up on Safari completely about six months ago.
Score: 3 Votes (Like | Disagree)
steve333 Avatar
61 months ago

I've been using Safari for more than 10 years, but the latest version is horrible honestly.
It has become very, very slow while I haven't changed anything about my setup or the way I use Safari. I also haven't added any new extensions. Same Mac, same everything. It also runs like crap even without any extensions, clear cookies, cache etc.

Web pages just keep freezing and make me wait for more than 10 sec for them to respond, double taps to zoom with the Magic Mouse make it freak out and lag so much. It makes my MacBook Pro freak out and the temps go high and so does the fanspeed...

I still use Safari because it's convenient with all the iCloud sharing between my iPhone and iPad. I hate to say it, but Chrome runs so, so much better, regardless what Apple's fancy speed bragging comparisons say. But I also don't wanna switch with everything to Google for obvious reasons.
I have the same issues as do many others, I have read forums here and on reddit about the problem. Do you also get a spinning beach ball when clicking on the bookmarks menu?

Interesting, you need to look elsewhere for what is going on, it’s not safari which works great
Yeah, it is Safari. See above. Worked great before Big Sur, works like garbage afterwards.
Apple isn't even acknowledging the issue. I opened a thread on Apple's support forums and they give the usual do this do that that fixes nothing, then they just left
Score: 2 Votes (Like | Disagree)
steve333 Avatar
61 months ago

If it was safari, I would have the problem too. So no, you are wrong, it is not safari. On the other hand, after the big chrome security issue recently, my safari would not load without crashing. I did a clean install, deleted chrome altogether and I am running completely fine. So not safari, not necessarily chrome, but fixed
Why are you having so much trouble believe this when others are having the issue with Safari (and Safari only) after upgrading to Big Sur?
Obviously there is an issue, could be a compatibility issue with certain machines, maybe certain chips or graphics cards.
Score: 2 Votes (Like | Disagree)
steve333 Avatar
61 months ago

it is simple, if it was safari and safari alone, it would be a universal problem, but it is not. why are you having so much trouble understanding that, it is a simple concept. Now, there may be something going on with people, something specific to their machines certain extension, even malware, even old libraries impacting the performance, but they are not simply Safari. Do a clean install, clean up all the crap, and it will work fine, it did for me.
If it happening only with safari, then it is a safari issue. Everything else, including firefox, works fine.
Score: 2 Votes (Like | Disagree)