SwiftUI text fade transition not animating in iOS 16+ – how to animate text content changes? (2026)

Summary

The issue at hand is related to animating text changes in SwiftUI, specifically with a fade transition, in iOS 16 and later. The current approach involves using the .transition(.opacity) modifier along with .id() to uniquely identify the text view and .animation() to specify the animation. However, the provided code does not produce the desired fade animation when the text changes.

Root Cause

The root cause of the issue lies in the misuse of the .id() modifier and the .animation() modifier. The .id() modifier is used to provide a unique identifier for the view, which is necessary for SwiftUI to correctly handle the transition. However, in this case, the .id() modifier is being used with a string that changes when the text changes, which defeats the purpose of providing a unique identifier. The .animation() modifier is also being used incorrectly, as it is being applied to the entire view hierarchy, rather than just the text view.

Why This Happens in Real Systems

This issue can occur in real systems when developers are trying to animate changes to a view’s content, but are not providing a stable identifier for the view. This can happen when the view’s identifier is based on the content itself, which can change over time. Additionally, incorrect usage of the .animation() modifier can also lead to unexpected behavior.

Real-World Impact

The real-world impact of this issue is that the desired animation is not being displayed, which can lead to a poor user experience. In this specific case, the text changes instantly without any fade animation, which can be jarring for the user.

Example or Code

struct TextAnimationView: View {
    @State private var textValue = "Hello"
    @State private var animate = false

    var body: some View {
        VStack(spacing: 50) {
            Text(textValue)
               .font(.largeTitle)
               .frame(width: 200, height: 200)
               .opacity(animate? 1 : 0)
               .animation(.easeInOut(duration: 1.0).delay(0.1), value: animate)
               .animation(.easeInOut(duration: 1.0), value: textValue)
            Button("Change Text") {
                withAnimation {
                    animate = false
                    textValue = textValue == "Hello"? "World" : "Hello"
                    animate = true
                }
            }
        }
    }
}

How Senior Engineers Fix It

Senior engineers would fix this issue by providing a stable identifier for the text view, and using the .animation() modifier correctly. They would also use a separate state variable to control the animation, and use withAnimation to ensure that the animation is triggered correctly.

Why Juniors Miss It

Juniors may miss this issue because they may not fully understand how the .id() and .animation() modifiers work, or how to use them correctly. They may also not be aware of the importance of providing a stable identifier for views, and how this can affect the animation. Additionally, they may not be familiar with the withAnimation function and how it can be used to trigger animations.