Speed Up Your Android App: 3 Image Optimization Tips for Jetpack Compose

Overview

Unoptimized images slow down your Jetpack Compose app and increase uninstall rates. These three tips - server-side compression, WebP format, and lazy loading - improve performance without sacrificing quality. This guide explains each tip with a beginner-friendly example for lazy loading.

Image Optimization Tips Table

Tip	Benefit
Server-Side Compression	Reduces image size before download, speeding up load times.
WebP Format	Smaller file sizes than PNG/JPEG with similar quality.
Lazy Loading	Loads only visible images, improving scroll performance.

Tip 1: Compress Images Server-Side

Use a backend or CDN (e.g., Cloudinary, Imgix) to compress images before they reach your app. This reduces file sizes, speeds up downloads, and lowers APK size.

How to Implement:

Sign up for a CDN like Cloudinary.
Upload images and use their API to generate compressed URLs (e.g., https://res.cloudinary.com/your-account/image/upload/q_auto/your-image.jpg).
Use these URLs in your app’s image loader.

Result: Faster image loading with minimal client-side processing.

Figure 1. Reduced load times with server-side compression.

Tip 2: Use WebP Format

WebP images are smaller than PNG or JPEG, offering better compression without visible quality loss. Convert your images to WebP using tools like Android Studio or online converters.

How to Implement:

In Android Studio, right-click a PNG/JPEG in res/drawable, select “Convert to WebP.”
Use WebP images in your app (e.g., @DrawableRes R.drawable.image).
For server images, ensure your CDN delivers WebP (e.g., Cloudinary’s f_webp parameter).

Result: Smaller image sizes, faster downloads, and lower memory usage.

Figure 2. Smaller file sizes with WebP.

Tip 3: Lazy Load Images in Jetpack Compose

Load only visible images in a scrolling list using LazyColumn and Coil’s AsyncImage. This improves scroll performance and reduces memory usage.

Beginner-Friendly Example:


import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.runtime.Composable
import coil.compose.AsyncImage

@Composable
fun LazyImageList(images: List) {
    LazyColumn {
        items(images) { imageUrl ->
            AsyncImage(
                model = imageUrl,
                contentDescription = "Image",
                modifier = Modifier.fillMaxWidth()
            )
        }
    }
}

How to Use:

Add Coil to your build.gradle:


dependencies {
    implementation("io.coil-kt:coil-compose:2.7.0")
}

Create a file named LazyImageList.kt in your ui package.
Copy the code above into the file.

Add it to your app’s UI, e.g., in MainActivity.kt:


@Composable
fun App() {
    val images = listOf(
        "https://via.placeholder.com/150",
        "https://via.placeholder.com/150",
        "https://via.placeholder.com/150"
    )
    LazyImageList(images)
}

Sync your project: ./gradlew build
Run the app: ./gradlew installDebug

Result: Images load only when visible, improving scroll performance.

Figure 3. Smooth scrolling with lazy loading.

Do i need Image Optimization Tips?

FAQ

Why optimize images in Jetpack Compose?

Unoptimized images slow down your app and increase uninstalls.

How does WebP help?

WebP reduces file sizes compared to PNG/JPEG, speeding up downloads.

What is lazy loading?

Loads only visible images in a list, improving scroll performance.

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Speed Up Your App: 3 Image Optimization Tips