The latest iPhone 16 Pro prototype modifies previous versions of the Action and Capture Buttons.

The Action Button replaced the Ring/Silent switch on last year’s iPhone 15 Pro models. Users can use this button to control one of numerous functionalities. The Action Button functionality can be altered at any moment, and the list includes:
You can toggle the silent mode on and off, just like the button that the Action Button replaces.
Turns on or off a specific focus.
Camera instantly launches the camera app to capture a photo, record a video, or take a selfie, portrait, or portrait selfie.

Switches the flashlight on and off.
Voice Memo starts and stops a voice memo recording.
The magnifying app is launched when you press the magnifier button.
Text is translated from one language to another using the translate command.
Opens a program or executes your preferred shortcut.
Accessibility displays an accessibility option.
There has been no action taken.

The Action Button is expected to appear on all four iPhone 16 models later this year, and the early iPhone 16 Pro prototypes showed that the Action Button will be in a solid state, responding to the user’s touch rather than being a physical, mechanical button. Apple reportedly claimed to be experimenting with the new Action Button’s size, with one prototype tested being as large as the volume buttons on the iPhone 16 Pro.
However, adjustments have been made as Apple enters the “Proto2” design stage for the iPhone 16 Pro. Apple has tested four button configurations, including a unified volume button with a small action button, a unified volume button with a large action button and a capture button, and separate volume buttons with a large action button and a capture button flush with the frame, according to MacRumors.
The fourth and current arrangement, which is being tested on the iPhone 16 Pro prototype, features distinct volume buttons, a small action button (the same size as the action button on the iPhone 15 Pro), and a capture button flush with the frame.
The Capture Button is supposed to start video recordings with a tap, and earlier prototypes showed that button on the right side of all iPhone 16 models, beneath the power button. Because 5G iPhone models in the United States have the mmWave 5G antenna on that side of the phone, iPhone 16 models in the United States will have to switch the 5G mmWave antenna to the left side if that configuration is employed. However, according to the most recent render spotted on MacRumors, the capture button is located on the left side, beneath the volume controls.
The capture button will be capacitive, which means it will respond to the user’s finger contact rather than mechanically.

Because we still have eight months until Apple introduces the iPhone 16 series, the design of the phone’s buttons is still changing. Don’t worry if your preferred button arrangement isn’t the most recent one being evaluated. Changes are still possible.