Summary of "Flutter vs ReactNative vs KMP: The TRUTH About Performance!"

Cross-Platform Mobile Development Performance Benchmarking

The video presents an in-depth, month-long performance benchmarking comparison of major cross-platform mobile development technologies: Flutter, React Native, Kotlin Multiplatform (KMP), and Android Native. The focus is on objective performance metrics including scroll performance, memory usage, CPU usage, animation performance, startup times, and build times. Two test applications were used—a lightweight scrolling app and a more complex app animating 200 images concurrently.

Key Technological Concepts and Product Features

Performance Metrics Measured

Memory Usage: Flutter consistently uses the most graphics memory, while Android Native uses the least. KMP performs better than React Native but worse than Android Native.
CPU Usage: Android Native generally shows the lowest CPU usage. Flutter and React Native have similar CPU usage in some cases.
Scroll Performance: Flutter struggles with smooth scrolling implementation compared to others. React Native lacks fine control over scroll speed.
Frames Per Second (FPS): FPS during scroll is roughly similar across Flutter, KMP, and Android Native (~90+ FPS), with React Native showing unusually high FPS (120), but no clear winner.
Animation Performance: Flutter leads in FPS when animating 200 images, followed closely by Android Native, React Native, and then KMP.
Startup Time: Flutter surprisingly has the fastest cold startup time (~0.7 seconds), beating Android Native (~1.4s), KMP (~1.2s), and React Native (~1.6s).
Build Times: Inconclusive due to differences in clean build procedures, but React Native and KMP have faster clean build times (~31 seconds) compared to Flutter (~1 minute 19 seconds).
APK Size: Flutter has the largest APK size (~12 MB), React Native next (~11 MB), with KMP and Android Native being the smallest (~6 MB).

Technical Adjustments and Improvements

Updated projects to latest versions and architectures (e.g., React Native new architecture).
Added KMP and Android Native implementations to existing benchmark apps.
Fixed image caching inconsistencies in Flutter to ensure fair comparison.
Developed a cross-platform communication channel to accurately measure “time to full display” (app fully drawn) for startup time.
Used Android GPU profiling tools for consistent FPS measurement across platforms.

Analysis and Results

Overall Winner: Android Native scored the highest (7 points), showing the best performance in most categories.
Runner-ups: Flutter (4.5 points) and KMP (3 points) performed well but with notable trade-offs.
React Native: Scored lowest (1.5 points) in these benchmarks but is still viable depending on use case.

The video stresses that these benchmarks represent worst-case scenarios and real-world performance may vary. The choice of technology remains subjective, influenced by developer needs, team expertise, and project requirements.

Guides and Tutorials Provided

Detailed explanation of benchmarking methodology and measurement techniques.
Insights into how to upgrade React Native projects using tools like React Native Upgrade Helper.
Tips on measuring startup times accurately, including overriding Flutter’s internal behavior.
Demonstration of profiling tools and how to interpret FPS and resource usage data.
Link to GitHub repository with the benchmark code for community review and experimentation.

Main Speakers / Sources

The video is presented by an independent developer/researcher who forked and extended repositories by:

Nadesh Bud (Proto vs React Native benchmark)
Jacob Ras (Proto vs Native vs KMP benchmark)

The presenter also references active engagement with developer communities (Discord, Reddit) and plans further content including blog posts and conference talks.

Summary

This video offers a comprehensive, data-driven comparison of Flutter, React Native, Kotlin Multiplatform, and Android Native focusing on performance metrics. Android Native emerges as the top performer overall, while Flutter impresses with startup times and animation FPS but consumes more memory and has larger APK size. React Native lags behind in some areas but remains relevant. The analysis emphasizes objective benchmarking, transparency in methodology, and encourages viewers to explore the open-source code and related videos for a broader understanding.