This page presents updated and high-quality Android Service interview questions and answers tailored for freshers and junior Android developer interviews in 2026. Each question is answered clearly with industry-standard explanations to help you succeed in technical screens and on-site rounds.
1. What is an Android Service?
An Android Service is a core application component that runs in the background without a user interface. Services perform long-running operations such as music playback, file downloads, or background synchronization independent of an Activity’s UI lifecycle.
2. Why Use a Service Instead of an Activity?
Unlike Activities, Services:
- Don’t have a UI
- Can continue running even when the user switches to another app
- Are suitable for tasks that must run in the background without user interaction
This makes Services the right choice for audio playback, downloading files, or handling scheduled tasks.
3. What Are Different Types of Services in Android?
Android Services are broadly categorized into:
🔹 Started Service
Started by startService() and runs until it stops itself or the system kills it.
🔹 Bound Service
Created with bindService(), providing a client-server interface to interact with the service.
🔹 Foreground Service
Runs with higher priority and shows a persistent notification to indicate ongoing work.
🔹 Background Service
Runs without UI; however, Android 8.0+ imposes restrictions on background execution, making WorkManager or foreground services preferred for long tasks.
4. Explain the Android Service Lifecycle.
A Service has unique lifecycle callbacks:
- onCreate(): Called once when the service is created
- onStartCommand(): Called each time a client starts the service
- onBind(): Provides binder interface when clients bind
- onUnbind(): Called when all clients unbind
- onRebind(): Invoked when a new client rebinds
- onDestroy(): Clean up resources before service termination
These callbacks help manage initialization, interaction, and cleanup properly.
5. How Do You Start and Stop a Service?
To start a service:
Intent intent = new Intent(this, MyService.class);
startService(intent);
To stop a service:
stopService(new Intent(this, MyService.class));
Or the service can stop itself using:
stopSelf();
6. What Is the Difference Between startService() and bindService()?
- startService(): Starts the service for independent execution; it keeps running until stopped.
- bindService(): Binds client components to the service; it runs only while at least one client is bound.
Use binding for interaction and retrieving results from the service.
7. When Would You Use a Foreground Service?
Use a Foreground Service when the user must be explicitly aware that a task is running — for example:
- Music playback
- Fitness tracking
- Real-time navigation
Foreground services require a persistent notification to comply with modern Android policies.
8. What Is the Difference Between a Service and an IntentService?
Historically, IntentService extended Service for handling asynchronous work on a worker thread and automatically stopped itself on completion. While useful, IntentService is mostly deprecated in favor of WorkManager and modern concurrency solutions.
9. What Are Limitations of Background Services?
Android 8.0 (API level 26) and later restrict background services for battery and performance. For deferrable background work, use WorkManager or a Foreground Service.
10. How Do You Communicate Between a Service and an Activity?
Common approaches include:
- Binding with ServiceConnection
- Broadcasts
- Messenger or AIDL
- LiveData or reactive streams (like Kotlin Flow)
Use the appropriate pattern based on complexity and interaction patterns.
11. What Is AIDL and When Is It Used?
AIDL (Android Interface Definition Language) enables inter-process communication between the service and clients running in different processes. It defines methods that clients can invoke on a remote service.
12. How Do You Make a Service Work Even After App Is Closed?
To keep a service running after the app exits:
- Use a Foreground Service with a foreground notification
- Use WorkManager for reliable deferred tasks
Background services alone are not reliable in modern Android versions due to execution limits.
13. What Is the Role of onStartCommand()?
The onStartCommand() method handles each request to start the service. It returns values like:
- START_STICKY: Restart the service if killed
- START_NOT_STICKY: Don’t restart
- START_REDELIVER_INTENT: Re-deliver the last intent
This return value controls how the system manages the service lifecycle.
14. What Is a Bound Service Used For?
Bound services are ideal when client components need:
- Interaction with the service
- Data exchange
- Callbacks and direct communication
Use ServiceConnection and an IBinder implementation for this pattern.
15. What Is the Difference Between Service and Thread?
A Service is an Android component that manages background work, while a Thread is a Java construct for concurrent execution. Services by default run on the main thread, so background logic should still be moved to threads or executors.
Recommended Preparation Tips
- Understand modern Android background execution limits
- Know when to use WorkManager vs. Service
- Practice code samples for starting, binding, and stopping services
- Understand lifecycle callbacks deeply
Summary
This page equips you with updated Android Service interview questions and answers relevant for freshers in 2026. It focuses on modern platform behaviors like background restrictions and best practices.
