Insights

Size Analysis Insights point out opportunities to reduce your Android app's size. They spot patterns like duplicate files, oversized media, or unneeded assets, and list exactly what to fix along with the estimated size savings.

Android Insights

Below are a list of available insights for Android builds, followed by more details about each insight:

Duplicate Files

What it is: Finds matching files or directories inside assets/, res/, or embedded libraries. Duplicate files are determined by examining the file hash, ensuring these are truly duplicates and not just similar files or the same file name.

How to fix: Keep one copy and remove or dedupe the rest. For resource folders, consolidate the asset into a shared module or asset pack so the APK only bundles it once.

Large Images

What it is: Flags image files larger than 10 MB.

How to fix: Compress images with lossless WebP or resize them before bundling.

Options:

• Use Android Studio: right-click an image → Convert to WebP → select Lossless.

• Use the command line:

  Bash

  Copied

  # Install cwebp
  brew install webp
  
  # Convert PNG to lossless WebP
  cwebp -lossless input.png -o output.webp
  
  # Convert JPEG to lossless WebP
  cwebp -lossless input.jpg -o output.webp
  

Large hero images or splash screens may also load more efficiently if served over the network instead of being bundled with the app.

Large Videos

What it is: Highlights bundled video assets above 10 MB.

How to fix: Re-encode them to H.264 or HEVC with a lower bitrate, shorten the clip, or host the video remotely and stream it on demand. To shrink a clip in place, try FFmpeg:

ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset slow -c:a copy output.mp4

Lower the -crf value for higher quality (and larger files), or raise it for smaller files.

WebP Optimization

What it is: Tests every PNG, BMP, JPG, or JPEG (excluding .9.png) against lossless WebP conversion. If the WebP variant saves at least 500 bytes, the insight lists the asset.

How to fix: Convert the listed bitmap to lossless WebP and update its references. Pick one of the paths below.

Option 1: Android Studio

1. In Android Studio, right-click the image.
2. Choose Convert to WebP….
3. Select Lossless (API 18+ supports it) and review the preview.

Option 2: Command line

# Install cwebp
brew install webp

# Convert PNG to lossless WebP
cwebp -lossless input.png -o output.webp

# Convert JPEG to lossless WebP
cwebp -lossless input.jpg -o output.webp

Lossless WebP with alpha requires minSdkVersion ≥ 18. For older devices, keep PNG fallbacks for assets that rely on transparency.

Large Audio

What it is: Surfaces audio files larger than 5 MB across res/raw, assets, or libraries.

How to fix: Re-encode them at a lower bitrate or modern format using FFmpeg or your DAW, trim unused segments, or stream long-form media instead of bundling it. A quick FFmpeg recompress:

ffmpeg -i input.wav -c:a aac -b:a 128k output.m4a

You can tweak the bitrate (b:a) to balance quality vs. size. Higher bitrates (192k-256k) will be higher quality, but larger size. Lower bitrates (96k-128k) will be lower quality, but smaller size. If your audio file is voice-only, you can use a lower bitrate with little degradation in quality. Music files may benefit from a higher bitrate.

Hermes Debug Info (RN Only)

What it is: Detects Hermes bytecode bundles that still contain debug info sections.

How to fix: Build the React Native bundle in release mode (react-native bundle --dev false or the Gradle release task) so Hermes strips debug sections before packaging.

Multiple Native Library Architectures

What it is: Detects when multiple native libraries are packaged in an APK supporting different architectures. End user devices will only use one architecture (usually arm64_v8a), so most can be removed.

How to fix: Upload an AAB to the Play Store (Google will automatically pass the architecture the end user needs). We also recommend you upload an AAB for size analysis.

If you ship an APK, the split {} block can be used to output split APKs manually. If configured to skip ABI splits, Android will package all native library architectures into the main split.

Ensure your split Gradle dls config has the isEnabled = true field set for the abi {} block.

android {
  splits {
    ..

    abi {
      isEnabled.set(true)
    }
  }
}

More information about the ABI configuration for manual APK splits can be found in the Android developer documentation.