So you have a great app idea for Android devices but you don’t know whether to use Java or Kotlin for the development of your app?

In this article we will show you the strengths of the 2 most famous programming languages for Android ​​so that you can answer the question.

Java or Kotlin?

When you think of Android App Development , which programming language comes to your mind first? It is likely to be Java, having over 20 years of history. But there are also other new languages like Kotlin that are challenging the leadership of Java.

This year, Google announced that Kotlin is now its preferred programming language for Android. It is a  relatively new language which is intuitive, modern and pragmatic.

At Appify, we’re here to help you decide which programming language (Java or Kotlin) works best for your next app development project. And since we imagine that you have heard much more often about Java, let us talk about Kotlin first.

Kotin: what is it?

Kotlin is an open source programming language designed and updated by JetBrains programmers.

This language is compatible with Java (says it all), designed to solve some Java development problems and to simplify the code for the creation of mobile apps.

Two years ago, in May 2017, Kotlin became a supported language by Google for Android and this was only the beginning of the competition between Java and Kotlin. Many developers loved it immediately and it began to grow in usage very quickly.

The increasing demand required the development of new versions which made it the ideal language for the development of multi-platform apps, for both Android and iOS.

Kotlin has found itself to be the preferred language not only by Google, but also by important brands that are famous in all over the world.

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But why did Google choose Kotlin?

The answer lies in the features of Kotlin that overcome the limitations of Java and that, today, represent an advantage for many developers.

Kotlin benefits


Kotlin is a faster programming language than Java. It requires less code. This reduces the probability of bugs and errors and makes the development process faster. Kotlin’s concise nature allows developers to read and modify code more efficiently which can reduce a project’s time-to-market. That’s the main reason why many developers prefer Kotlin to Java.

code Java or Kotlin


One of best features of Kotlin is its ability to interact and work with its rival, Java.

From the beginning, the goal of the Kotlin project was to use existing knowledge and skills to make every Java library available to Kotlin programmers.

This means that developers can use a series o Java libraries to create modules with Kotlin and, at the same time, thanks to a converter created by JetBrains, they can generate Java code from Kotlin.

Basically, the 2 programming languages can work together on the same project. The transition from Java to Kotlin is very simple for a developer due to the affinity of the two languages and the conversion tools available.


Another very important feature of Kotlin is the security of its architecture. It helps to avoid the most common errors that developers encounter in Java like the NullPointerException which can cause the system to block or crash.

Kotlin has eliminated the the possibility of having this error, reducing the possibility that Android mobile apps get stuck in the middle of an operation.

Java: what is it?

Java is a programming language originally developed by James Gosling at Sun Microsystem in 1995, currently owned by the Oracle CorporationJava is considered one of the best languages for app development. It’s a reliable programming language, with many tools and open source libraries, used by many developers all over in the world.

Java development dominates the world of business applications, thanks to extraordinary features such as interoperability and flexibility.

Java is present almost everywhere: in laptops, video game consoles, smartphones, etc. And thanks to constant updates, the apps developed in Java are always protected and efficient.

Java programming language

Why to choose Java for Android app development?

This programming language is easy to learn and understand. It is flexible and it’s part of the Android SDK (System Development Kit). But let’s see what are its advantages.


Java programs can be run on almost any system thanks to the platform-independent Java Virtual Machine (JVM). Automatic memory management makes it usable on a wide range of devices, from large networks to personal PCs.

Great community

As Java has a long history,. It is evident that the number of Java developers is greater than those of Kotlin, which is a newer programming language. And as the community is bigger it’s easier to get support from other members. The Java community keep the programming language up-to-date and can, thanks to that, solve almost all the problems and bugs of their code.


The apps developed in Java are compact and light compared to those achievable with Kotlin. Kotlin can require complex code processing which can slow performance.


The Java programming language is not limited to the development of Android apps – it also supports cross-platform app development.

Java or Kotlin: which programming language to choose for your next Android app?

We have identified the advantages of both Kotlin and Java languages and the differences between them. Regardless of all the differences between the two programming languages, some features are better in Kotlin while for others Java is more advantageous. So should you use Java or Kotlin for the Android App Development?

Well, there is no right or wrong answer to this question.

But there is a solution: interchangeability.

These 2 languages are completely interpretable. This makes it easy to introduce Kotlin into a Java project, and at the same time, it allows the simultaneous use of the two languages ​​in any Android application development project.

But if you really have to make a choice, remember that it always depends on the complexity of the project you intend to carry out.

At Appify, we have an award-winning team of developers who have a deep knowledge in Kotlin and Java development. We are able to create Android apps for all customer needs. Our development process consists of 5 phases which allows us to carry out detailed and accurate projects that use the best programming languages ​​for the specific case.

For this we evaluate the project together with our clients to be sure that it corresponds 100% to their requirements.

If you’re still hesitating whether to choose Java or Kotlin, lean on our experienced developers!

Our professionals will help you develop your Android application on a reliable, safe and compatible platform. Feel free to contact us also if you need any level of Android support. We will contact you as soon as possible to arrange an appointment.