Apple’s first iOS 27.3, iPadOS 27.3 and macOS 27.3 betas turn Safari into a more tab-friendly browser. The developer betas add a vertical tab layout, Adaptive Dark Mode, and Siri AI actions for tabs. 9to5Mac reports the builds landed on 3 November, and our full iOS 27.3 beta rundown covers the Health app and the rest of the update. Here’s a closer look at what changes in the browser itself.
Vertical Tabs move the tab bar to the side
Vertical Tabs are an alternative to the usual horizontal strip. They sit on the left side of the display and use icons by default to save space, with an option to widen the bar so website titles show as well. That makes them a natural fit for wide screens, and MacRumors notes the layout pairs well with the iPhone Duo’s larger display, though it’s available across iPhone, iPad, and Mac.
The sidebar doesn’t replace Apple’s existing tab organisation. According to MacRumors, Vertical Tabs work with both Topics and Tab Groups, and Topics are the categories Safari creates when automatic Apple Intelligence tab sorting is on in iOS 27. Pinning tabs by dragging and swapping quickly between Tab Groups carry over too.
The timing is pointed. 9to5Mac says Arc, from The Browser Company, popularised vertical tab layouts, but Arc ceased development last year and The Browser Company announced last month it will shut it down in December. Safari’s sidebar arrives just as one of the browsers that made the layout popular is going away.
Adaptive Dark Mode handles sites that ignore your settings
Adaptive Dark Mode targets the bright white page that still appears when you’ve set your device to Dark Mode. If you browse to a site with a bright background, Safari offers a “Try” option. MacRumors says tapping it makes Safari render a dark version of the page that darkens the background, changes text contrast, inverts logos and graphics, and recolours vector artwork. It also lifts raised surfaces and rebalances layered shadows, and not every adjustment is applied to every site.
After you’ve tried it, you can turn Adaptive Dark Mode on for all sites or choose site by site. It stays out of the way on pages that already have a dark design. Safari won’t activate it on a site with a native dark mode, and developers can add a tag that makes Safari ignore the feature and show the site as intended. That opt-out matters for brands with strict colour rules, since the feature recolours logos and artwork automatically.
Siri AI gets hands-on with your tabs
The third change is voice and text control. Siri can sort, move, close and arrange tabs in Tab Groups, and it can clear your web history for a particular site over a set period, such as the last 10 days. MacRumors’ beta guide adds that Siri can also save articles to a Reading List and close duplicate tabs.
A bigger Siri upgrade is coming, but it isn’t in this beta. Siri can already see what’s on your screen, and Apple says it will soon understand the full content of webpages, including non-active tabs and content out of view. In MacRumors’ example, you could ask it to sort a pile of shopping tabs by price. That awareness feature isn’t in the first beta, and the Siri features need an Apple Intelligence-capable device.
For readers in the region, language support is the open question. Our earlier coverage found that Siri AI’s supported languages don’t include Arabic, so the tab commands may be less useful for Arabic speakers until Apple widens support. Vertical Tabs and Adaptive Dark Mode are visual features and don’t depend on Siri.
How do I turn on Vertical Tabs in the iOS 27.3 beta?
On iPhone, open Settings, choose Apps, tap Safari, then look for the Vertical Tabs option. On Mac and iPad you can also enable it from the View menu in Safari.
Do I need an Apple Intelligence device to use the new Safari features?
MacRumors says the Siri features need an Apple Intelligence-capable device. Apple hasn’t been quoted on a hardware requirement for Vertical Tabs, so check the beta on your own device before relying on it.
When will iOS 27.3 reach everyone?
MacRumors says iOS 27.3, iPadOS 27.3 and macOS Golden Gate 27.3 launch this December after several rounds of beta testing. Betas are the earliest builds and can be buggy, so we’d keep them off a daily-use device and wait for the release.
