Apple has released the first developer betas of 27.3 and Safari is getting three new features: vertical tabs, adaptive dark mode, and more Siri AI.

Vertical tabs in Safari with iOS 27.3
The 27.3 update is looking like a huge one for Apple, with new features across all of Apple’s platforms. The new Health app has made its return, Apple Watch is getting new Siri AI features, and Apple Intelligence is coming to China.
Then we have Safari on iPhone, iPad, and Mac that is seeing a trio of substantial new features.