iPhone users can set custom Messages backgrounds in iOS 26, visible to all chat members

iOS 26 introduces a new Backgrounds option inside the Messages thread details screen, allowing users to pick a static color, a dynamic animation, or a personal photo from their camera roll. The selection can be made for both one-on-one chats and group conversations. Once chosen, the background replaces the default white backdrop for that thread. The change is reflected instantly and a system note records who made the adjustment and when.

Adopting the feature requires devices running iOS 26, iPadOS 26, macOS Tahoe, watchOS 26, or visionOS 26, and the setting is enabled by default. Because the background is shared, any user who sets a custom image unintentionally exposes that image to every other participant in the chat. Engineers must treat the background as a piece of conversation state that is replicated across all clients, similar to a group-chat name change. This may necessitate updates to client-side logic that assumes per-user theming is isolated.

The feature stops working as a per-user customization when any member of the conversation is on an older operating system that lacks the Backgrounds option; those users see the default background instead. Turning off Conversation Backgrounds in Settings hides the image locally but also removes it for everyone else in the thread. Selecting None per thread likewise clears the background for all participants. Consequently, the only way to have a background visible to just one user is to use a client-side overlay that is not part of the official Messages API.