Java vs Kotlin: Key differences you should explore

java vs kotlin

What are the factors that determine an impressive, delicious dish? The chef’s skill and the freshness of ingredients, right? Likewise, to create an appealing website or app, besides developers, you also need to choose the best programming language. Today, let’s discover Java vs kotlin – 2 of the most common ones.

ArrowHiTech is glad that you are joining us today. Then, we will go through the definitions, then key differences and comparison of Java vs kotlin.

Without further ado, let’s get started!

What is Java? What is Kotlin?

Java vs kotlin are 2 popular programming languages.

Java is an OOP (object-oriented programming) language and was created in 1995 by Oracle.And, with 25 years of development, Java has now become a globally known for supporting lots of apps and especially web browsers. Besides, it is available on multiple operation platforms such as Linux, Windows, Mac, … Especially when it comes to Android apps, most developers would adopt Java right away.


Kotlin is a rather new programming language developed in 2011 by IDE Jet Brains. However, the first official release was in 2016. Although Kotlin is based on JVM like Java and C++, it is also available on iOS and Android.

kotlin java

To switch from Java to Kotlin, all you need is to install a plugin.

Both of the 2 have different strengths and weaknesses. Thus, to figure out which is the most suitable for you, you need to compare them regarding multiple aspects.

Java vs Kotlin: Comparison Table

Developmentin 1995, developed by Sun Microsystemsin 2016, developed by JetBrains
Null Safety
(Java vs kotlin)
– NullPointerException is the most common problem
– Allow users to assign null
– No null pointer exception issues
– By default, all variables are non-null-able
Checked Exceptions– Checked exceptions
– Robust code with error handling from developers
No checked exceptions feature
Type InferenceNeed specification of each variable while declaringNo need to specify the type of each variable
Data Classes
(Java vs kotlin)
– Class that holds data (only data)
– Define constructors, variables to store data, getter-setter methods, hashcode(), toString() and equals() functions
– Class that holds data (with keyword)
– Create constructors, getter-setter methods
Operator OverloadingNo supportProgrammers can define the operators
SemicolonStatement must be terminated by semicolon(optional) Write semicolon at the end of statements
Smart CastsCheck variable type and castUse keyword “is-checks”
Functional ProgrammingOnly till Java 8Is a combination of functional programming languages
App Size
(Java vs kotlin)
– Android: smaller size
– Gradle: faster speed
– Android: larger size
– Gradle: slower speed
Code Sizemore codes30-40% fewer codes
Co-routines SupportCreate multiple threads in the background and run. Yet, it’s complex to manage themCreate multiple threads to run long-running intensive operations
Extension Functions Not availableCreate by prefixing class name to new function

Read more about:

Java framework: 20 most popular and useful frameworks you should study

So, which is better?

Both java vs kotlin have benefits and drawbacks but we need to fully understand each’s strengths to see which fits you best!

Kotlin’s Advantages

  1. Firstly, support for Smart cast that can identify the immutable types and performs implicit cast by compiler.
  2. Secondly, support for type inference that requires no data type specification.
  3. Lastly, Interchangeability with Java

Java Advantages

  1. Support for checked exceptions that can perform error handling
  2. Much faster compilation time than Kotlin
  3. Ability to assign null values

Until now, java vs kotlin, you must have made up your mind on which programming languages that you prefer. Then, what is the next step? You’d better hire experts to have them implemented and custom made for you.

How to implement java vs kotlin? Call AHT NOW!

Hiring experts to install your favorite theme is a reasonable investment to save time, money and work. After all, working in IT outsourcing for over 13 years, ArrowHiTech is proud to be a leading Vietnamese company and a trustworthy front-end developer that provides optimal solutions and services worldwide.

Our experts are glad to help you out on any IT problems with our consistent strengths:

  • Rich Experience: Founded in 2007, today, we are one of the leading IT outsourcing companies in Vietnam. We have managed to complete more than 10,000 projects worldwide. Thus, language borders are non-existent when working with us!
  • Low Cost: Located in Vietnam, our labour fee is extremely affordable. Furthermore, we always provide a wide range of profitable selection with different prices. As a result, any customers can choose their favorite and suitable ones.


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  • Strong Dedication: We believe that dedication and passion is the core value which results in the optimal working experience. With that in mind, Our team always prioritizes customers’ needs and demands.

Since our development, ArrowHiTech has always prioritized customers and your satisfaction. We believe that commitment, integrity and passion are what make us stand out and trusted for many years. Therefore, we would love YOU to be our next long-term partners for any web development problems.

Final Words

Thanks a lot for joining us on the topic of Java vs Kotlin comparison today.And, we hope that you can easily know their differences and choose the best one for yourself. If you have more relating issues, check out our Android app development services or contact us at:

AHT welcomes every comment and feedback! As always, we wish you the best of good luck and success!