react native session replay causes very noticeable screen freezing once every second

[bj97301]

What React Native libraries do you use?

Expo (mobile only)

Are you using sentry.io or on-premise?

sentry.io (SaS)

@sentry/react-native SDK Version

"^7.7.0"

How does your development environment look like?

npx react-native@latest info
info Fetching system and libraries information...
System:
  OS: macOS 26.1
  CPU: (20) arm64 Apple M1 Ultra
  Memory: 3.29 GB / 128.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.19.4
    path: ~/.nvm/versions/node/v20.19.4/bin/node
  Yarn:
    version: 1.22.22
    path: ~/.nvm/versions/node/v20.19.4/bin/yarn
  npm:
    version: 11.6.2
    path: ~/.nvm/versions/node/v20.19.4/bin/npm
  Watchman:
    version: 2024.10.21.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.1
      - iOS 26.1
      - macOS 26.1
      - tvOS 26.1
      - visionOS 26.1
      - watchOS 26.1
  Android SDK:
    API Levels:
      - "30"
      - "31"
      - "32"
      - "33"
      - "33"
      - "34"
      - "35"
      - "36"
    Build Tools:
      - 27.0.3
      - 28.0.3
      - 29.0.3
      - 30.0.2
      - 30.0.3
      - 31.0.0
      - 32.0.0
      - 33.0.0
      - 33.0.1
      - 33.0.2
      - 34.0.0
      - 35.0.0
      - 36.0.0
    System Images:
      - android-33 | Google APIs ARM 64 v8a
      - android-34 | Google APIs ARM 64 v8a
      - android-UpsideDownCake-ext5 | Google APIs ARM 64 v8a
      - android-UpsideDownCake-ext5 | Google Play ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2025.1 AI-251.26094.121.2513.14007798
  Xcode:
    version: 26.1.1/17B100
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 21.0.7
    path: /usr/bin/javac
  Ruby:
    version: 2.7.6
    path: /Users/Bryan/.rvm/rubies/ruby-2.7.6/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.2
    wanted: ^20.0.2
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.5
    wanted: 0.79.5
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

info React Native v0.82.1 is now available (your project is running on v0.79.5).
info Changelog: https://github.com/facebook/react-native/releases/tag/v0.82.1
info Diff: https://react-native-community.github.io/upgrade-helper/?from=0.79.5&to=0.82.1
info For more info, check out "https://reactnative.dev/docs/upgrading?os=macos".

Sentry.init()

Sentry.init({
  dsn: 'https://...@sentry.io/...'
   tracesSampleRate: 1.0,
    enabled: true,
    debug: environmentConfigs.isProduction(),
    environment: environmentConfigs.environment,
    dist: Platform.OS,
    normalizeDepth: 0,
    replaysSessionQuality: 'low', // i also tried the v2 stuff but no luck still freezes my screen once every second
    replaysSessionSampleRate: 0.1,
    replaysOnErrorSampleRate: 1,
    integrations: [
      Sentry.mobileReplayIntegration({
        maskAllText: false,
        maskAllImages: false,
        maskAllVectors: false,
      }),
      Sentry.userInteractionIntegration(),
    ],
})

Steps to Reproduce

1. enable replays
2. scroll

Expected Result

scrolls smoothly

Actual Result

freezes every second

[linear]

RN-415

[antonis]

Thank you for reporting @bj97301 🙇
Do you observe the delay on both iOS and Android? Is this reproduced both on development and release builds?
Could you also share your project dependencies (package.json) to investigate possible conflicts that may cause the observed behavior?

[bj97301]

Thank you for reporting @bj97301 🙇
Do you observe the delay on both iOS and Android? Is this reproduced both on development and release builds?
Could you also share your project dependencies (package.json) to investigate possible conflicts that may cause the observed behavior?

Yes both but on android it's more of a massive performance hit rather then freezing every second.

Both dev and prod builds. Dev builds are less performant as expected.

I will work on the package in a bit. You just want to see dependencies?