WebKit has posted a new Safari Technology Preview build for macOS Golden Gate and macOS Tahoe. Release 256 is a preview download, not a regular Safari update that shows up on its own.
Grab the build from the official release page, install it, then open About Safari Technology Preview and confirm the version reads 256 before you start testing sites.
In this guide, I have covered:
Contents
Release 256 is out for macOS Golden Gate and macOS Tahoe
Your Mac is on macOS Golden Gate or macOS Tahoe and you want to know whether this new WebKit post applies to you. It does. Safari Technology Preview Release 256 is available for download on those two versions.
The official WebKit release notes are dated November 5, 2026.
The post names Safari Technology Preview, not a stable or beta Safari build. It confirms the download and stops there: no phased rollout, no staged schedule to wait on.
WebKit lists macOS Golden Gate and macOS Tahoe for Release 256. The announcement does not list iPhone, iPad, or other macOS versions.
How to download and install Release 256 on Mac
Installing this build is a download and a double-click, not a system upgrade. If your Mac runs one of the two listed versions, get it straight from the official WebKit release page.
- Open the official Safari Technology Preview 256 release page.
- Download the Release 256 build offered for your macOS version.
- Open the downloaded file.
- Complete the installation steps shown on screen.
Launch Safari Technology Preview when the installer finishes. Confirm the version before you test anything.
This procedure installs Safari Technology Preview as its own app. The announcement does not state that it updates or replaces the regular Safari app.
How to check the installed preview version
You installed the build, but you still need proof that the app is running 256 and not an older copy. Read the About screen first.
- Open Safari Technology Preview.
- Open the app menu.
- Choose About Safari Technology Preview.
- Confirm that the version number reads 256.
You’ll know it worked when About shows 256. If it shows an earlier build, return to the official download and finish the installation before testing.
What to check before you start testing
The WebKit entry confirms the build and which macOS versions run it. That is all it gives you. For implementation details, read the full official release notes rather than assuming a particular behavior changed in Release 256.
If the site you’re checking looks wrong on a phone, switch Safari to a mobile layout before you file it as a bug: view the mobile site layout in Safari on Mac.
A page that keeps serving an old version is usually a stale cache, not the preview. Clear the DNS cache in Safari and reload before blaming Release 256.
Frequently Asked Questions
Which macOS versions support Safari Technology Preview 256?
WebKit lists macOS Golden Gate and macOS Tahoe for the Release 256 download. No other platform is named in the announcement.
Is Safari Technology Preview 256 a regular Safari update?
No. The official announcement covers Safari Technology Preview 256 only and says nothing about a stable or beta Safari rollout.
Is Release 256 rolling out in phases?
There is no phased schedule to wait for. The release entry confirms that the build is available for download and stops there.
How do I confirm that Release 256 is installed?
Open About Safari Technology Preview. A version number of 256 means you have the build described in the WebKit announcement.
Does this announcement cover iPhone or iPad?
No. The release entry names only macOS Golden Gate and macOS Tahoe, so there is no iPhone or iPad version of Release 256 to install from it.
