Android App Startup Time: What Makes Apps Slow

A fast startup makes an Android app feel premium. A slow startup makes even the best app feel heavy, unreliable, and outdated.

Startup performance is one of the first things users notice. If your app shows a blank screen, takes too long to load, or feels stuck on the splash screen, users often leave before they even experience the product.

This article explains what startup time really means on Android, what causes slow launches, and how to fix startup bottlenecks in real production apps.

What startup time means in Android

Android startup is usually divided into three categories:

Cold start

A cold start happens when the app is not in memory at all. This is the slowest startup type and the most important to optimize.

Warm start

A warm start happens when the app process exists, but the activity must be recreated.

Hot start

A hot start happens when the activity is already in memory and can resume quickly.

Most user complaints come from cold starts, especially on older devices or phones under memory pressure.

The biggest reasons Android apps start slowly

Startup slowdowns usually come from too much work happening before the first screen becomes visible.

Too much work in Application.onCreate()

This is one of the most common performance killers.

Typical examples:

initializing many SDKs immediately
heavy dependency injection startup
reading files or databases synchronously
configuring analytics, logging, or remote config too early

The more work you do here, the longer users wait before seeing UI.

Third-party SDK initialization is often the real bottleneck

Many apps are slow not because of their own code, but because of third-party SDKs.

Common culprits:

analytics SDKs
attribution SDKs
crash reporting SDKs
ads SDKs
social login SDKs

Even if each SDK takes a small amount of time, the combined cost adds up quickly at startup.

Slow startup is often a “main thread problem”

Startup performance is heavily affected by how much is executed on the main thread.

If your app blocks the main thread during launch with:

I/O
heavy computation
reflection-based initialization
large object graph creation

…startup time increases dramatically, and can also lead to jank or ANRs.

Keep the first screen simple and load the rest later

A key principle is that the user should see something meaningful quickly.

Good startup design:

show the first screen fast
load data progressively
defer heavy work until after the first frame

Apps that feel fast do not load everything at startup. They load what matters first.

Avoid doing database work during startup

Loading the database too early is a common mistake, especially in offline-first apps.

Database work at startup can cause:

slower cold start
delayed navigation
heavy memory allocation

A better approach is to:

show UI immediately
fetch database content asynchronously
render placeholders and update when data arrives

Reduce dependency injection overhead

Dependency injection frameworks can improve architecture but can also slow startup if configured poorly.

Startup overhead often comes from:

creating too many singletons immediately
scanning modules eagerly
initializing feature graphs that aren’t needed yet

A scalable approach is to create only what you need for the first screen, then initialize other components lazily.

Baseline profiles can make startup noticeably faster

Startup speed is not only about code. Runtime optimization also matters.

Baseline profiles help Android pre-optimize important startup code paths. This can reduce:

cold start time
initial screen render time
early UI jank

Apps with baseline profiles often feel smoother immediately after installation, especially on devices that benefit from ahead-of-time compilation improvements.

Measure startup correctly before optimizing

Startup optimization should always be driven by measurement.

The best approach is to:

measure cold start time
identify the expensive startup operations
fix them one by one
measure again after each change

Without measuring, it’s easy to optimize the wrong thing and gain nothing.

Use a splash screen correctly

Splash screens are often misused.

A splash screen should:

appear instantly
never block startup intentionally
disappear as soon as real UI is ready

If your splash screen stays too long, users assume the app is slow—even if the app is working fine in the background.

Common startup mistakes to avoid

doing network calls during startup
initializing every SDK immediately
heavy work in Application.onCreate()
database queries before first screen is visible
large object graph creation at launch
delaying UI until everything is ready

FAQ

What is the best way to improve cold start time quickly? The fastest improvement usually comes from reducing work inside Application.onCreate() and deferring SDK initialization until after the first screen is visible.

Can slow startup cause ANRs? Yes. If the main thread is blocked long enough during startup, the system can trigger ANRs, especially on slower devices.

Are baseline profiles worth it? Yes. Baseline profiles can improve startup and early performance without changing app behavior, and they are especially helpful for large apps.

Fast startup is not about doing more work faster. It’s about doing less work before the user sees UI.

The biggest startup wins come from minimizing work in Application.onCreate(), deferring non-critical tasks, reducing third-party SDK startup cost, moving heavy work off the main thread, and measuring improvements consistently.