Kotlin or Java for Android App Development Which One Should You Choose ?


24 Apr 2023

Android app development is a big and ever-growing industry. Kotlin or Java for Android App Development lets understand more about these technologies.

With the increasing number of Smartphone users, more and more people are digging into the app development space. However, one needs to master a programming language to begin Android app development.

When it comes to picking a language for app development, an array of choices are available. But two of the most popular ones include Kotlin and Java.

Kotlin is the official programming language for Android app development whereas Java has been used for the past 20 years. It’s still widely in use by many mobile app development companies but Kotlin is becoming more popular nowadays.

If you are confused about making the right choice between the two, read this article to decide which would be the right to go for.

Background of  Kotlin or Java for Android App Development



Java was introduced to the programming world in 1995 by Sun Microsystems. It’s a modern object-oriented, high-level, and class-based that supports multiple platforms.

Kotlin is a statically typed general-purpose and object-oriented programming language that was first designed for Java virtual machine and then become an official language for Android app development.

Java is mainly an object-oriented programming language whereas Kotlin even supports functional programming. Like this, several others differences make one better than the other.

Community Support

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Both Java and Kotlin are open sources which makes their community bigger and easier to collaborate.  There are around 5.9 million Kotlin developers so it won’t be wrong to say that the community is still in the growing phase because many developers are still fond of Java, considering its 20 years old history of development. More than 10 million Java developers are there in the world.


Unfortunately, Java lacks the support of extension functions. If you want to enhance the functionality of the existing class, it will consume a lot of time. You can save time with Kotlin as it offers a strong capability of extending the functions of an existing class. For that, simply put the prefix of the class to the function name.


Developers love to program in the Kotlin language because it eases to build multithreading applications. But at the same time, the compilation time increases. Java will perform better in compiling but still, this has nothing to do with the performance. Eventually, both of the programs first convert to byte code and then run on the Java virtual machine.

If you want to enjoy fast compiling and are ready to write more code, Java would be an ideal choice. Kotlin is good for someone who doesn’t want to write much code but knows how to leverage its automation capabilities to get something done faster.


If you ask the developers, many of them will agree that programming in Java is complicated. In fact, code in Kotlin appears more clear, more concise, and more readable.


Every developer knows that building scalable web applications requires a lot of resources. Complexity in an application can cause serious performance issues and as it happens you may find that your application is slow or inflexible to process requests.

That’s the reason why Kotlin stands out as a preferred choice even by any Android app development company in India or outside. It emphasizes more on building a scalable solution to run smoothly on the latest Android models without any interruption.

Learning Curve

Kotlin Or Java For Android App Development

An inexperienced developer will have a hard time learning Java. Kotlin has an expressive coding syntax so you can learn it in less time than it will take to understand Java.

Smart Casts

Some of the functions in Java are performed manually which consumes the developer’s time. This also includes the inspection of variables as per the operator which takes plenty of time.

It’s managed in Kotlin with the help of the smart cast feature as it manages to cast checks, replacement of redundant tasks, and more. However, note that it only works when the compiler can ensure the variable remains unchanged during check and usage.

Time Consumption

 Coding in Java can be a little bit time-consuming when compared to Kotlin. This is because more lines of code are needed to be written in Java whereas you can get a particular task done with less code.

But things get tricky due to the cognitive load in Kotlin. That’s why an abstract thinker will feel more comfort in coding with Kotlin rather than Java.

Data Classes

In java based app programming, setting up fields or variables is necessary for data storage. You have to make the constructor, getter, and setter functions, hashCode (), etc. However, Kotlin users don’t have to do all these because it allows the automation of such tasks.

To take the advantage of automation, just add the “data” keyword in the class definition. After that, compiles will see the creation of variables, constructors, and more.

Which and when to use?

Among them, Java will fit perfectly for apps that require a lot of functionality and features. Its extensive library enables smoother development of such apps.

Kotlin is most appropriate for apps where performance holds a lot of importance. For instance, a photo editing app or something that will be run on old Android phones. In addition, it’s a good choice when you want the app across multiple platforms.


In the end, the choice of using one over the other will depend on your personal preference; convenience; and the project need. Both have their drawbacks and advantages so you have to be careful in making the selection. Don’t be in hurry or else you will end up messing up everything.

The good part is Java and Kotlin can be used together without affecting the progress of your app project. But if considering the current situation and Google’s future goals, it would be best to choose Kotlin over Java. Better to see what suits you or which language fees convenient for your mobile app development company in Bangalore and then just go with it.