Java is a staple of Android app development. Kotlin is a hopeful newcomer that aches to take over the future. Which one is the right choice? Fortunately, this article looks at both. You will get a glimpse of why you might stick to the tried-and-true Java programming or get into the exciting Kotlin Mobile App Development.

Introduction to Java

This programming language has been around since 1995. How does it do this? Reliability. Anyone can benefit from this in their app development process. This is why the Google Play store hosts many Java-built applications. Furthermore, Android OS devs used Java for large parts of the system. Access to Java libraries in this case is advantageous. This language is a sound choice for anything from apps on the web to Big Data tools.

Introduction to Kotlin

Kotlin is young and fascinating. It is a statically-typed open-source Java Virtual Machine language. JetBrains built it to tackle features that Java cannot. Google named it the preferred language for Android app development in 2019, adding to its credibility. This has paved the way for Kotlin to gain its place on the Android scene. Moreover, it looks like it will rise in popularity in the future. A Stack Overflow survey from 2019 places this language in the top five most loved ones. In the year 2020, 8% of more than 47 thousand professional developers picked Kotlin first. This is a better number than 6.6% in the previous year.



Java is one of the most active languages on Github. In 2021, it still is a tool of choice for many developers. This object-oriented language simply never stopped growing. Java keeps attracting loyal and knowledgeable members to its community. Fortunately, this gives beginners a good starting point. A deep cave of Java knowledge may surprise even experts. Never has a vast library been a disadvantage – a 25+ year history has generated many ready-to-use solutions and a plethora of handy modules.


Google declares that these days over 60 percent of professional Android developers use Kotlin. That means its community is rapidly growing and maturing. The official documentation is sufficient for beginners, yet it is still a challenge to find solutions. This is where experience matters. Nonetheless, the code is open-source and the community is on the rise. Kotlin will satisfy your abstract thinking needs if a little discovery is what you’re after. Studying it might indeed prove more engaging for beginners than plunging into Java. An experienced developer who already knows the latter will find Kotlin a great time investment.

Coding experience


Java syntax is verbose. Unfortunately, this means more possibilities for mistakes. Another concern is memory use, yet experts’ opinions here often diverge. It is not entirely clear how big of a difference it makes in comparison with other languages. One thing is notable, however – Java-built applications turn out to be smaller. They are easier on the device and more agile. As a result, they may serve the end user better, even if a beginner made them. A well-oiled machine like Java will provide robust and speedy development if one gets used to the syntax. Better yet, the language keeps evolving to this day. It is good to see it become simpler without losing its time-proven reliability.

Now for some of the unique technicalities. Java’s members are static, exceptions are checked, and fields are mostly nonprivate. Java is also an established choice for cross-platform development. This is because old code still makes sense after any updates and can run just as well in a browser as on a virtual machine.

It is no secret that many other programming languages are Java derivatives. Thus, knowing Java will prove invaluable for anyone looking to make an app. It’s simply impossible to ignore a great deal of useful but specific libraries that will not work with anything else.


Kotlin aims to modernize Java for the modern Android app development environment. One of its main features is that one does not need to abandon Java entirely. You may transition as much or as little as desired.

The language simplifies Java syntax, making coding more efficient and productive. Companies like Twitter, Netflix, and Uber, among others, value this. It seems that they are increasingly turning to Kotlin for their development needs. On the other hand, some say that simpler code might obstruct readability. Thankfully, the substance is not lost with Kotlin. Indeed, this comes with the price of having to get used to doing things differently. Therefore, this difference between Kotlin and Java might hinder a team’s progress during development.

Java has other issues apart from brevity. Users are happy that Kotlin made them easier:

  • Invariant arrays were previously impossible;
  • Kotlin doesn’t need checked exceptions;
  • Kotlin provides a robust type system with built-in null safety. It protects you from NullPointerExceptions that used to break Java code;
  • Java was behind on useful features. Kotlin hasstring templates and smart casts, for example.


Which language is the most suitable option for your app?

Java is recommended for beginners. It boasts a vast resource base to pick from when starting. Many solutions are already out there. Thankfully, the community is still huge. Is Java reliable? Yes. It indeed takes more time to type it out, but the learning curve is smoother thanks to Java’s long-time leading position on the scene.

Kotlin is great in three cases:

  • if an application has an eye towards the future;
  • if it does not need necessarily need to be cross-platform;
  • if you already know Java.

If anything of the above is true, make use of Kotlin’s novelty. Its efficiency doesn’t compromise quality. Android app development in the next five years? It will become more Kotlin-oriented.

Still can’t choose between Java and Kotlin? Shockingly, a great way to move forward. Master both languages. They coexist fruitfully at the moment. Android developers who don’t make use of both languages’ strengths are seriously missing out.