Avoid Android App Crashes: Kotlin Best Practices

You know that moment when you're rushing to book a cab, the payment is about to go through, and suddenly the app freezes? For a few seconds, you're stuck - did the payment go through or not? Do you retry? Do you close the app? That tiny moment of uncertainty is enough to frustrate most users. And more often than not, they don't come back.

That's exactly how silent damage begins in mobile apps. Not with big disasters—but with small, unexpected failures in moments that matter most. On Android, even one crash in a critical flow like login, checkout, or onboarding can quietly push users away, hurt your ratings, and impact revenue. While no app can ever be completely crash-proof, Kotlin gives you a strong safety net to reduce these risks long before users feel them.

Avoiding Crashes

1. Null Safety with Kotlin

A surprising number of Android crashes still come down to one simple problem: something was null when the app expected it not to be. A missing API field, a delayed user input, or an object that wasn't initialized in time - any one of these can take your app down instantly.

This is where Kotlin quietly protects you. Unlike older languages, Kotlin forces you to acknowledge uncertainty up front. If a value can be missing, the compiler makes you handle that possibility before the app ever reaches a user's phone.

For example:

var name: String? = null   // Nullable value
name?.length              // Safe call - no crash if name is null

That single ? changes everything. Instead of crashing at runtime, the app simply moves on safely. Over thousands of real-world sessions, these small safeguards add up to a massive reduction in unexpected failures.

2. Exception Handling

Even with the best precautions, things can still go sideways. Maybe an API call fails, a file isn't found, or some unexpected input sneaks in. If you don't handle these exceptions, your app crashes - and just like that, a user drops off.

Kotlin gives you a way to catch these surprises before they reach the user. Wrapping risky code in try-catch blocks lets your app respond gracefully instead of just stopping cold.

try {
    // Some operation that might fail
} catch (e: Exception) {
    // Handle it safely — log it or show a friendly error message
}

It's simple, but it works. By catching exceptions, you can log them for later analysis, provide helpful feedback to the user, and keep your app running smoothly. Handling exceptions properly turns what could be a crash into a small hiccup the user barely notices.

3. Defensive Programming

Sometimes the crash isn't caused by anything "wrong" in your code—it's just bad luck. A user enters unexpected input, an API returns something weird, or a list you assumed had 5 items only has 3. Defensive programming is all about expecting the unexpected and guarding your app against it.

For example, when accessing a list, always make sure the index exists before using it:

val list = listOf(1, 2, 3)
if (index in 0 until list.size) {
    val item = list[index]
    // Safe to use 'item'
} else {
    // Handle the unexpected index
}

These small checks feel tedious at first, but they save your app from crashes and your users from frustration. Think of it as putting up a safety net before walking a tightrope - better safe than sorry.

4. Robust API Calls

Networks are unreliable by nature. Even on the best connections, timeouts happen, packets drop, and servers misbehave. When apps assume every request will succeed, crashes become inevitable.

Robust networking means planning for failure from the start:

• Timeouts instead of infinite waits
• Retries instead of dead ends
• Validations instead of blind trust

An API failure shouldn't feel like an app failure to the user. At most, it should feel like a temporary delay - because that's usually what it is.

Reporting Crashes with Appxiom

Even with all the right precautions in place, crashes will still happen. Devices differ. OS versions behave inconsistently. Hardware limitations show up in ways you can't simulate. This is where visibility becomes more important than prevention.

1. Integrating Appxiom into Your App

First, sign up for an Appxiom account. Then, add the Appxiom SDK to your Android project by including this in your build.gradle file:

dependencies {
    implementation 'com.ax:axcore:x.x.x'
}

Next, initialize Appxiom in your Application class so it can start monitoring your app as soon as it launches:

import android.app.Application

class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        Ax.init(this)
    }
}

And just like that, Appxiom is ready to quietly track crashes, performance hiccups, and other issues, giving you insights before your users even notice.

Capturing and Reporting Crashes

Appxiom keeps an eye on your app 24/7. It automatically captures crashes and unhandled exceptions, collecting critical details like the stack trace, device information, and even the sequence of user actions that led to the issue.

If you want to track non-fatal errors too, you can report them manually with a few lines of code:

try {
    // Code that might throw a non-fatal exception
} catch (e: Exception) {
    Ax.reportException(this, e, Severity.MAJOR)
}

Beyond crashes, Appxiom also monitors things like memory leaks, slow frames, API failures, and 30+ more bugs, giving you a complete view of your app's health in development, testing, and production.

3. Analyzing Crash Reports

Raw crash data is just noise until you turn it into action. The real advantage of structured crash reporting is pattern recognition.

You start to see:

• The same crash repeating on one Android version
• A memory issue affecting only low-end devices
• A failure that appears only after long user sessions

Instead of guessing what to fix next, you prioritize based on impact. Fixes become targeted. Releases become safer. Over time, your crash rate stops fluctuating wildly and starts trending downward in a predictable way.

Closing Thoughts

There's no single line of code that makes an Android app "uncrashable." Stability comes from many small, unglamorous decisions repeated consistently - null checks, safe exception handling, defensive guards, resilient network calls, and real-world monitoring.

Kotlin helps you write safer code. Monitoring tools help you understand how that code behaves when real users interact with it in unpredictable ways. Together, they transform crashes from unpredictable disasters into manageable engineering problems.

And that's when stability stops being a hope - and starts becoming a process.