UI jank with Impeller on Android when using CustomScrollView

[motattack]

Steps to reproduce

1. Create a new Flutter project.
2. Replace the contents of main.dart with the code provided below in the Code sample section.
3. Build and run the app on a physical Android device using profile mode, with Impeller enabled.
4. Quickly scroll up and down in the list.

Expected results

Smooth and responsive scrolling.

Actual results

Noticeable UI jank and frame drops during fast scrolling. Performance is visibly worse in profile mode compared to when Impeller is disabled (i.e., when using Skia).

Code sample

Code sample

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: CustomScrollView(
          slivers: [
            const SliverAppBar(
              title: Text('Example'),
              centerTitle: true,
              surfaceTintColor: Colors.transparent,
            ),
            const SliverToBoxAdapter(child: SizedBox(height: 16)),
            SliverList(
              delegate: SliverChildBuilderDelegate(
                (BuildContext context, int index) {
                  return const Text('test');
                },
                childCount: 40,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Screenshots or Video

Screenshots / Video demonstration

impeller.mp4

skia.mp4

Logs

No response

Flutter Doctor output

Doctor output

C:\Users\mot>flutter doctor -v
[√] Flutter (Channel stable, 3.29.3, on Microsoft Windows [Version 10.0.26100.3775], locale ru-RU) [506ms]
    • Flutter version 3.29.3 on channel stable at C:\Users\mot\dev\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ea121f8859 (5 weeks ago), 2025-04-11 19:10:07 +0000
    • Engine revision cf56914b32
    • Dart version 3.7.2
    • DevTools version 2.42.3

[√] Windows Version (Windows 11 or higher, 24H2, 2009) [2,1s]

[√] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [3,6s]
    • Android SDK at C:\Users\mot\AppData\Local\Android\sdk
    • Platform android-35, build-tools 35.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.5+-12932927-b750.29)
    • All Android licenses accepted.

[√] Chrome - develop for the web [183ms]
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.13.6) [182ms]
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.13.35931.197
    • Windows 10 SDK version 10.0.22621.0

[√] Android Studio (version 2024.2) [28ms]
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.5+-12932927-b750.29)

[√] VS Code (version 1.100.1) [27ms]
    • VS Code at C:\Users\mot\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.110.0

[√] Connected device (4 available) [365ms]
    • SM A525F (mobile) • RZ8RC1N5W7Z • android-arm64  • Android 14 (API 34)
    • Windows (desktop) • windows     • windows-x64    • Microsoft Windows [Version 10.0.26100.3775]
    • Chrome (web)      • chrome      • web-javascript • Google Chrome 136.0.7103.93
    • Edge (web)        • edge        • web-javascript • Microsoft Edge 136.0.3240.64

[√] Network resources [2,0s]
    • All expected network resources are available.

• No issues found!

[darshankawar]

Tried the same on S10+ device in profile mode and do see the reported janks while scrolling.

stable : 3.29.3
master : 3.32.0-1.0.pre.494

[ciriousjoker]

For us, this also only happens on Android, not iOS (even on an old iphone se 2nd gen), but this isn't reflected in the tags.

[jonahwilliams]

The reported bug seems to be using an Android emulator for performance measurement. The Android emulator is not representative of on device performance.

[motattack]

No, that’s not an emulator. It's a real device - Samsung A52. I'm recording the screen via ADB, in case the window on the right threw you off.