Apple today seeded the fourth beta of iOS 27 to developers. Although this release introduces fewer significant changes, Apple is continuing to polish the overall user experience ahead of the public launch of iOS 27 in September. Below are the changes I’ve found in iOS 27 beta 4 so far.
In case you missed it, here’s everything added in beta 3: What’s New in iOS 27 Beta 3→
iOS 27 Developer Beta 4
Build: 24A5390f
Released: July 20, 2026
Siri AI
iOS 27 beta 4 adds a new “An All-New Siri” welcome screen that appears when you swipe down to launch Siri AI for the first time.
Apple has also added five new Siri voices with adjustable Expressivity and Pace, bringing the total to seven. However, only two of the new voices are currently available, while the remaining five are labeled “Coming Soon.”
Beta 4 also expands Siri’s English voice options by adding Australian, British, Indian, Irish, and South African voices alongside the existing American voice. However, these newly added voices do not support the Expressivity and Pace controls.
Bottom Lock Screen Control
iOS 27 beta 4 brings back the white control buttons at the bottom of the Lock Screen in both light and dark mode.
Today View
The blur effect has returned to the Home Screen’s Today View, just like in iOS 26.
Notification Center
The Depth Effect that appeared when opening Notification Center in Beta 3 is no longer present in iOS 27 Beta 4. It’s unclear whether this is an intentional change or simply a bug, as the effect disappeared just two weeks after it first appeared.
https://x.com/BetaProfiles/status/2079280143458316596
References to a Dual-Battery iPhone
Macworld spotted code in iOS 27 beta 4 that references an iPhone with two separate batteries, likely pointing to the rumored foldable iPhone Ultra. Here’s the relevant string found in the code:
The health of the batteries in this iPhone has significantly degraded, and one of the batteries could not be verified as a genuine Apple battery. An Apple Authorized Service Provider can replace the batteries to restore full performance and capacity.
According to rumors, the iPhone Ultra will pack two batteries rated at 1,921mAh and 2,962mAh, adding up to a combined 4,883mAh.
Volume Slider
The Liquid Glass volume slider is more transparent in iOS 27 Beta 4.
AirPods Slider
The AirPods controls in Control Center also get a major refresh. You can now press and hold to swipe between options with a smooth Liquid Glass animation.
https://x.com/BetaProfiles/status/2079324253187645596
Zoom Photos to Fill
A new Zoom Photos to Fill option has been added to the Photos settings and is enabled by default. It slightly zooms in on photos to better match your iPhone’s display aspect ratio.
Siri App
Under Settings → Siri, Apple has added a new Preview option that lets you choose how many lines are shown in Siri previews. You can select anywhere from 1 to 5 lines, or choose None to hide the preview entirely.
Camera Settings
If Apple ProRes is enabled under Settings → Camera → Formats, a new ProRes Log Video Encoding option appears, letting you choose between Log and Log 2.
According to Apple, Log 2 preserves more image information in each video file, giving you greater flexibility when color grading and making adjustments during post-production.
If you’ve come across any other changes, drop them in the comments below 
I’ll keep adding more iOS 26 Beta 4 changes and new features here as I discover them. Stay tuned and follow @BetaProfiles on X or Threads!
