Safari is finally getting vertical tabs, and that is only one part of what Apple is testing in the first developer betas of iOS 27.3, iPadOS 27.3 and macOS 27.3. The browser is also picking up an AI-driven dark mode for websites that never built one, plus deeper Siri AI controls that can read pages and manage tabs on command.
Vertical tabs are the least flashy change, but they may be the most welcome. Microsoft Edge, Vivaldi and, more recently, Firefox have offered side-mounted tab lists for some time, and Safari users have been asking for parity. A vertical list shows full page titles instead of truncated stubs, which makes a cluttered session much easier to scan. The feature works across Mac, iPad and iPhone, including the iPhone Duo. On Mac and iPad it can be turned on from the View menu, and on iPhone it sits in Safari’s settings.
Adaptive Dark Mode targets a familiar irritation: the system is set to dark appearance, and then a website loads with a full-white background. Many modern sites respect a device’s appearance setting, but plenty still don’t. Apple’s approach uses Apple Intelligence to assess each site on its own terms rather than applying a blunt colour inversion. Apple says the feature darkens backgrounds, adjusts text contrast, inverts logos and graphics where needed, recolours vector artwork and rebalances layered shadows on more complex layouts. It isn’t applied silently, either. When Safari detects a page that could benefit, a prompt appears at the top asking whether to enable it.
That matters because forced dark modes, from browser flags to extensions like Dark Reader, have a long history of mangling layouts and images. Whether Apple’s version does a better job is something the beta period will have to prove. Site owners who want their design left alone can add a tag to opt out.
The Siri AI additions push Safari closer to the agent-style browsing that rivals are exploring. Siri can now take in the full contents of a page, so asking how heavy a product is should pull that figure from a long listing. It can also act across tabs, grouping them, closing every tab from a specific site, or clearing a site’s history over a set number of days.
The 27.3 releases are expected to reach users in December, though beta features can slip. Some of the Safari changes will also come to macOS Tahoe, but Adaptive Dark Mode and Siri AI require Apple Intelligence-capable hardware. That leaves older devices with the tab redesign but without the more interesting tricks.
