Striking up conversations in Google Messages may soon feel a little unfamiliar

Google is apparently preparing another change for Google Messages, and like most recent updates, it's cosmetic.
When examining the code in the latest beta version of Google Messages, Android Authority spotted a new Start chat user interface. The revamped UI follows the same theme as the rumored updated search interface.
When examining the code in the latest beta version of Google Messages, Android Authority spotted a new Start chat user interface. The revamped UI follows the same theme as the rumored updated search interface.

The current Start chat Google Messages UI. | Image Credit - Android Authority
The changes might seem insignificant but for eagle-eyed Google Messages users, they are not subtle. However, they are also not massive enough to confuse you and nothing has been rearranged.
The first change is that the new interface has more rounded elements. The text input field at the top of the New conversation page is now pill-shaped instead of rectangular. The "Create group" button has been enlarged and is easier to spot now. Gemini now lives in a card with curved edges. There are now individual cards for each contact.
When a contact is selected on the "New group chat" page, it's put in a gray oblong container. Similar changes have been made to the "Add group name" page.
When a contact is selected on the "New group chat" page, it's put in a gray oblong container. Similar changes have been made to the "Add group name" page.

The upcoming Start chart interface. | Image Credit - Android Authority
These updates are believed to be part of an interface revamp initiative codenamed "Cool Ranch Phase 3."
The latest changes are not live yet and just because Google is experimenting with them doesn't necessarily mean that they will be rolled out publicly.
If Google does choose to deploy these changes, it could be a couple of months before we see them. That's the usual cadence with rumored features. As an example, the chat bubble animation that was leaked in January has only started to roll out now.
Another useful change that was made recently was a text field redesign that made it bigger. Similarly, the voice note shortcut was also enlarged.
Updates like these make the app, which is now the default messaging app for many Android users, more convenient to use.
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