Improve Android App Launch Speed with Google’s App Startup Library

The time it takes for an application to load has become one of the major factors affecting user retention. Research shows that even a few seconds of delay in start-up time may result in higher bounce rates and lower engagement of users, especially on mid-range phones. Ensuring your app loads fast is just good UX, but also a commercial necessity since millions of apps compete for users' attention.

Google made the App Startup Library, androidx.startup, publicly available to help developers overcome heavy initialization workloads and slow startups. This Jetpack component reduces app initialization overhead by systematizing and simplifying the initialization process, thus helping to reduce cold start time and improving both Time to Initial Display, TTID, and Time to Full Display, TTFD.

In this blog, we are going to explain how App Startup works, why it is important, and how you can use it to advance the performance of your app.

Why Do Android Apps Launch Slowly?

To understand how App Startup helps, it is important to identify what are the main causes of slow app launches:

1. Heavy Work in Application.onCreate()

Most apps perform a number of initializations within Application.onCreate(), such as database instances, SDK configurations, analytics, logging tools, etc. All this happens before the user even sees the first screen.

2. Several ContentProviders

Third-party or legacy libraries often register their own ContentProvider. Android instantiates each provider at startup, which causes a significant slowdown in cold-start performance.

3. Uncontrolled Order of Initialization

Many providers and SDKs initialize at boot, a process over which the developer has no control, in terms of either sequence or timing. This often leads to redundant or unnecessary work.
The App Startup Library excels in this situation.

How App Startup Library Speeds Up Launch Time

The App Startup Library provides a unified and efficient way to initialize components. It uses just one InitializationProvider and allows the developer to define exactly what is initializing and when, versus relying on multiple ContentProviders or intricate onCreate() logic.

Key Benefits

1. Replace Multiple Content Providers

App Startup reduces overhead and increases cold-start efficiency by consolidating initialization into a single mechanism.

2. Lazy and Eager Initialization

Greedy: Triggers itself once the app is started.
Lazy: Great for cutting down on initial load time; only runs when necessary.

3. Unambiguous Initialization Order

Declaring dependencies with the library makes sure that components initialize in the proper order without interfering with UI rendering.

How to Implement App Startup (Quick Example)

Step 1: Add the Dependency

implementation "androidx.startup:startup-runtime:1.2.0"

Step 2: Create an Initializer

class AnalyticsInitializer : Initializer<AnalyticsManager> {
    override fun create(context: Context): AnalyticsManager {
        return AnalyticsManager.initialize(context)
    }

    override fun dependencies(): List<Class<out Initializer<*>>> = emptyList()
}

Step 3: Declare Dependencies (Optional)

If another initializer depends on analytics:

override fun dependencies() = listOf(AnalyticsInitializer::class.java)

Step 4: Use Lazy Initialization (Recommended)

For components not needed immediately:

AppInitializer.getInstance(context)
    .initializeComponent(AnalyticsInitializer::class.java)

By carefully choosing which components should be eager or lazy, developers can dramatically reduce startup time.

Combine App Startup with Baseline Profiles for Maximum Speed

App Startup handles initialization for you, but you can amplify your startup optimizations by using it in conjunction with Baseline Profiles, R8 optimization, and Macrobenchmark testing.

Why this mix is effective:

• Android uses baseline profiles to precompile code that is startup critical.
• R8 does optimize bytecode for faster execution.
• Macrobenchmark measures a device's actual startup time.

Combined, these approaches can cut startup times by 20–40% on mid-tier devices, according to real-world case studies.

Best Practices for Improving Launch Speed Use lazy

• initialization whenever possible.
• Remove obsolete or unnecessary SDKs.
• Use StrictMode for finding intensive main-thread operations.
• Postpone making network calls until after the first frame.
• Use Macrobenchmark and Perfetto to measure progress.

The more pointless tasks you remove from the launch phase, the smoother your user experience will be.

Need help getting your app started, or fine-tuning performance?

The ability to optimize the startup time requires proficiency in initialization patterns, baseline profiles, performance profiling, and dependency management. You can always hire our team's experienced Android developers when you need experts to critique your app and implement changes with quantifiable results.

Conclusion

One of the best, and most developer-friendly, ways to make apps launch faster is Google's App Startup Library. It simplifies setup and improves user experience by substituting many ContentProviders, allowing lazy initialization, and giving you control over initialization order.

When combined with modern Android performance tools, this makes for a formidable strategy in crafting fast, efficient apps. In case you want a quicker app launch time then App Startup is the first step in your optimization process.