Android is always evolving, and sometimes those changes happen a bit under the hood. One such change that's been gaining traction—and now has a firm deadline from Google—is the move to a 16 KB page size. If you're an Android developer, especially with native code in your app, understanding this shift is really important for keeping your apps smooth and compatible.

Table of Contents

What is a Page Size?

Think of your device's memory like a book. An operating system doesn't read memory one tiny word at a time; it reads in chunks. These chunks are called "pages." For a long time, on most ARM64 Android devices, these pages were 4 KB in size. Now, for some newer Android devices (specifically those launching with Android 13 and later), that page size has quadrupled to 16 KB.

Why is this Change Being Implemented Now?

It's all about making Android run better on modern hardware. Here are some of the reasons why is it being implemented:

Better Performance: Modern processors can handle larger memory chunks more efficiently. A 16 KB page size means the CPU spends less time managing tiny bits of memory and more time doing actual work, which can lead to faster app performance.

Smoother Operations: With fewer, larger pages to keep track of, the system itself has a little less overhead, making things a bit more streamlined.

Keeping Up with Tech: This change helps Android align with how newer ARM64 processors are designed to work best.

What are the Pros and Cons of this Change?

Every big change has its own pros and cons.

Pros

  • Apps that move a lot of data around or are memory-intensive might just feel a bit snappier

  • The system could run a bit more efficiently, benefiting all apps indirectly

Cons

  • If your native code is constantly asking for very small bits of memory (less than 16 KB), each of those might now take up a full 16 KB page, potentially using a little more memory than before.

  • If your native code makes assumptions that "memory pages are always 4 KB," it could run into issues on 16 KB page devices.

Should You worry About this Change?

You need to pay attention if:

  • Your app includes native libraries (like .so files) written in C/C++. This is where the impact is most direct. If your native code does anything with memory mapping (mmap, shmem) or file I/O where it calculates offsets or sizes based on a fixed page size.

  • You're developing games or other highly performance-sensitive apps with native components.

  • You're targeting Android 15+ with your app updates.

You need not worry if:

  • Your app is built purely in Java or Kotlin with no native components. The Android Runtime (ART) handles memory for you, so these underlying page size changes are largely invisible. You'll still get the performance benefits!

  • You're using React Native or Flutter, unless you've added custom native modules that directly deal with memory mapping or page-size-dependent operations

Is this Mandatory?

Yes. Google Play is making this a requirement for app updates. You would have received an email from Google Play if your app does not support 16 KB page size yet.

Your app is affected by Google Play's 16KB page size requirements

As the screenshot clearly shows, "From Nov 1, 2025, if your app updates do not support 16 KB memory page sizes, you won't be able to release these updates" for apps targeting Android 15+. This gives us a solid timeframe to get things ready.

What if You Don’t Upgrade Your App?

You could notice some serious issues if your app has native libraries that aren't ready for the 16 KB page size by the deadline. Here are a few:

  • Crashes: This is the most serious. Your app might crash unexpectedly (often with a "segmentation fault") if it tries to access memory incorrectly due to old page size assumptions.

  • Wasted Memory: If your code allocates memory in smaller chunks than 16 KB, it could end up using more memory than necessary, potentially slowing things down or hitting memory limits.

  • Performance Hit: Instead of gaining speed, your app might actually run slower if its memory operations aren't aligned with the larger page size.

Essentially, your app might work fine today, but become unstable or inefficient on newer Android devices if its native components aren't updated.

How Does this Affect Hybrid Apps?

Generally, if you're building a standard hybrid app (React Native or Flutter app) without custom native modules, you're in a pretty good spot. The frameworks themselves, and the underlying runtimes (JavaScript engine for React Native, Dart VM for Flutter), usually handle memory management, abstracting away the page size.

However, if you've implemented custom native modules in C++ for performance-critical tasks or specific hardware interactions, then you do need to check those modules.

For the vast majority of standard React Native and Flutter apps, you likely won't need direct code changes related to page size, but always ensure you're using the latest SDK versions for your framework to benefit from any underlying platform updates.

What Would be the Code Change for This?

The biggest thing to avoid in your native code is making assumptions about memory page sizes. Instead of hardcoding 4096 (for 4 KB), always ask the operating system what its current page size is.

Steps to Take:

  1. Audit Your Native Code: Search your .cpp, .c, and .h files for any direct use of 4096 or 4 KB in memory allocation, buffer sizing, or alignment calculations

  2. Replace with sysconf(_SC_PAGESIZE) or getpagesize(): Update any fixed values to dynamically retrieve the actual page size.

  3. Recompile with Latest NDK: Make sure you're building your native libraries with a recent Android NDK (r25 or newer is a good target). This ensures your toolchain is aware of the 16 KB page size and provides correct system definitions.

How to Verify if Your App is Upgraded to a 16 KB Page Size

You can verify if your app is upgraded by running extensive testing. However, here are the few more steps.

  1. Check Your Test Device's Page Size:

    • Connect your Android 13+ test device (preferably a newer one like a Pixel) via ADB

    • Run adb shell getconf PAGE_SIZE

    • If it returns 16384, you're testing on a 16 KB page device! If it returns 4096, you'll need to find a different device to properly test for this change

    • Here’s an example screenshot from my device

      Find page size of an Android device/emulator

  2. Run Your App Extensively: Once you have a 16 KB page device, put your app through its paces. Try all features, especially those involving native code, heavy data loading, or complex operations.

  3. Monitor for Crashes: Keep a close eye on your crash reporting tools (like Crashlytics). Specifically look for native crashes (SIGSEGV, SIGBUS) coming from Android 13+ devices, as these could be related to page size issues.

  4. Memory Profiling: While less direct, if you suspect memory inefficiency in your native code, use Android Studio's Memory Profiler to see if allocations are unexpectedly large or if there's excessive memory usage.

Conclusion

In this blog, we learnt about page size in Android, and why and how to upgrade your app to support 16 KB page size. I hope you have a clear idea about 16 KB page size in Android. By being proactive now, you can avoid last-minute scrambling and ensure your apps continue to perform beautifully on the latest Android devices, well past the November 2025 deadline!

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