Slashdot has reported:

Apple is adding vertical tabs and Adaptive Dark Mode to Safari in December software updates for iOS 27.3, iPadOS 27.3 and macOS Golden Gate 27.3. The updates will also expand Siri’s browser controls, including tools to organize tabs and clear history for specific websites. A later feature is planned to let Siri understand and answer questions about content across multiple open webpages.

Vertical Tabs appear along the left side of the display, using icons by default to save space. Users can widen the tab bar to see website titles, and the layout works with Topics and Tab Groups. Topics are created when automatic Apple Intelligence tab sorting is enabled in iOS 27. Pinning tabs by dragging and quickly switching between Tab Groups will remain available.

Adaptive Dark Mode is designed for websites that do not offer a dark mode. When someone using Dark Mode visits a site with a bright background, Safari will offer a “Try” option. Selecting it produces a darker version of the page, adjusting the background and text contrast, inverting logos and graphics, recolouring vector artwork, lifting raised surfaces and rebalancing layered shadows.

Safari will adapt each site according to what is needed for readability, so it will not apply every adjustment to every page. After trying the feature, users can enable it for all websites or choose sites individually. It will not activate on websites with a native dark mode or an already dark design. Developers can add a tag instructing Safari to ignore Adaptive Dark Mode and display their site as intended.

The details were reported by MacRumors and relayed by Slashdot. Apple’s December updates bring the new Safari options across its iPhone, iPad and Mac platforms, while the planned Siri feature for questions about multiple webpages is described as a later addition.