WebKit

WebKit's November 13 post says developers most likely need do nothing for Safari on Apple HomeView, then flags recipe JSON-LD for its cooking view, an iOS user agent and a viewport shorter than 600px.

WebKit says Safari 27.3 beta's Adaptive Dark Mode darkens light pages for users who enable it but leaves alone pages that declare dark-mode support; the opt-out keyword it names is unsupported in beta 1.

WebKit's Safari 27.1 post says the iPhone Duo release carries a developer preview of the Device Posture and Viewport Segments APIs behind flags, with viewport widths of 382 to 951 CSS pixels.

In its iOS, iPadOS, macOS and visionOS 27 releases, WebKit blocks network access to identity resolution services at the domain level, so they cannot receive users' email addresses.

Safari 27.0 folds its Safari MCP developer server into a stable release, adds CSS-styleable select dropdowns, and rewrites the module loader in native C++.