Kotlin vs Groovy: An In-depth Comparative Analysis

While both Kotlin and Groovy are simpler renditions of Java, the previous is more suited for Android app development, and the latter as a scripting language.

Updated 6 March 2024


CTO at Appventurez

The resounding presence of Android in the mobile operating system’s market share calls for a premier and proficient programming language. Up until the end of the preceding decade, Android app development mostly mandated expertise in Java. The power and prowess of Java are known in the programming world. However, languages were built over Java for further efficiency, convenience, and suitability with programming for Android. Amongst them, two frameworks, Kotlin and Groovy have risen in ranks in the developers’ favorites list the most. Yet developers transitioning from Java, or looking for the best option for Android app development seem to have sparked the Kotlin vs Groovy discourse.

Fundamentally, compiling and packaging the project and managing dependencies during development between Groovy vs Kotlin is done on the build automation tool, Gradle. Moreover, Groovy is a functional language, while Kotlin is both functional and procedural. That implies that the latter can be used to formulate both simple and custom functions. 

There are endless features that make these two languages stand out. Let’s delineate the contrasts and find out the better off Kotlin vs Groovy.

Kotlin: The Modern Android Language

Kotlin is a high-level, open-source Java-based programming language developed by JetBrains and executable on Java Virtual Machine (JVM). The language was statically written with concise syntaxes to cut down on the need for boilerplate codes. This feat is particularly essential when it comes to Android programming. Kotlin interface follows an aggressive type to process values and procedures, and thus, despite the affinity with Java, its syntaxes aren’t compatible with it.

Kotlin offers a blend of attributes from top languages including Java, C#, Javascript, Scala, and so on. In certain specifications, Kotlin provides an improved solution such as in operator overloading. But it’s also not as consolidated as Java when it comes to the ternary operator and checked exceptions. Both languages are interoperable and can be utilized altogether.

Adoption By Google

Since its launch with Apache open-source license in 2011, Kotlin’s steady rise in popularity and acceptance amongst developers put it under Google’s purview. It was initially launched to be used as a plugin in Android Studio. Later, in the 2017 Google I/O conference, Kotlin was declared the official language for Android app development. It comes as an alternative to the Java compiler in the current version, i.e., Android Studio 3.0, and is also an integral part of the Android SDK.

As of now, the community presence of Kotlin is growing. Owing to its rapid spread in tech it can be predicted that in the short span, an intensive developer ecosystem will surface and pull in lots of projects.

Benefits of Using Kotlin For Android App Development

The survey that Kotlin is the third-most in-demand language developers plan to migrate to by 2022 shows its explosive rise in popularity. Android app developers have taken note of the benefits of using Kotlin, and its extended utility in web and cross-platform mobile app development as well. Let’s review the advantages of Kotlin in detail.

  • Kotlin code structures are concise— As previously mentioned, coding in Kotlin is a succinct exercise. The code structures are condensed while redundancies and boilerplate codes are eliminated. This makes development reliable, improves productivity, and renders enhanced code security.
  • It averts runtime errors— Owing to the accuracy Kotlin functions upon, instances of app crashes and runtime errors are lessened to zero. Such flawlessness in applications in turn betters user experience.
  • It’s equipped with a fail-fast mechanism— Kotlin is incorporated with a fail-fast system to detect and report any bugs and errors in the codebase. In the case of one, the process collapses, allowing developers to promptly fix the issue before moving ahead. For this functionality, three library functions, namely, check, require, and assert are deployed.
  • It offers null safety— Kotlin doesn’t permit the passage of null pointers without reference to other statements. It immediately shows a NullPointerException (NPE) in such a case and delivers null safety.
  • Smart type casting— Unlike Java and many languages, Kotlin performs smart type casting on the variable to access its attributes. An operator is used to inspect the variable type and cast it into the target type.
  • It is interoperable with Java— Kotlin’s execution on the Java Virtual Machine (JVM) enables it to operate alongside Java. It can also build dependencies with Java Class Library to run specific procedures.

Groovy: The Java Enhancer

Groovy is much older than Kotlin, the first version being released in 2007. It is an object-oriented functional programming language built on Java. Similar to Kotlin, it is deployed upon the Java Virtual Machine (JVM) and interoperates efficiently with Java codebases. It allows both static typing and dynamic typing identical to Java and Python respectively.

Groovy can also be utilized as a scripting language and identifies with Javascript. Corresponding to Kotlin, Groovy’s syntaxes are like that of Java with a few alterations. The codes are condensed and provide developers with flexibility in implementing functions. This attribute has earned the ‘Java Enhancer’ metonym amongst developers. Amongst the many Android app development frameworks, Groovy is left to be used mostly for scripting.

In addition, Groovy can also effectively render Native support, operator overloading, and deployment of markup languages like HTML and XML. Its utility also extends to testing IDEs and Java tools like Ant and Maven.

Benefits of Groovy For Android App Development

The longevity of Groovy and its object-oriented character separates it from Kotlin. While on the scale of wider acceptance among the developers, Groovy seems to gain steady momentum. Nevertheless, its utility has been lasting and the following features remain in demand.

  • Static and dynamic typing functionality— Groovy enables type checking both during compilation and execution. Both static and dynamic typing, as is separately in the case with Java and Python respectively, are executable through Groovy.
  • Direct and condensed syntax— Compact code syntaxes assure programmers of a speedy project development process and an efficient method to execute functionalities.
  • Easier to learn— Groovy is comparatively easier to learn than Ruby or Python and facilitates an effortless switch from Java.
  • Testing-focused environment— Groovy is a testing-oriented language and enables the function to execute tests in integrated development environments (IDEs), Maven, and Ant.
  • Support for native syntax for associative arrays— Arrays are threads of information relayed through variables. Developers at times use this method for greater efficiency. Groovy allows such a way of indexing and outputting information.
  • Support for markup and domain-specific languages— Groovy supports markup languages like HTML and XML. It also allows the functioning of languages meant to perform distinct tasks as opposed to generic syntaxes.

Kotlin or Groovy For your Android App Project

Groovy vs Kotlin: Juxtaposing The Languages

For mobile app development, choosing between the JVM-based languages Kotlin and Groovy, it is imperative to compare the depth of technicality and utility between the two languages. In many aspects, Kotlin has already been accepted as a standardized language for Android app development. However the utility of Groovy in rendering specific technical functionalities cannot be ignored. Therefore, to ascertain the better option of the two, a comparative analysis is conducted below.

Kotlin vs Groovy — utility


Since Kotlin’s adoption in 2017 as the official language for Android, its paramount application is in Android app development. Its utilization is also widely noted in developing server-side programming due to interoperability with Java.

Popular tech companies have wielded Kotlin in executing custom functionalities that include—

  • Instant business communication platform Slack’s Android client is developed in Kotlin.
  • For their Android app, Pinterest, like many apps migrated from Java to Kotlin for greater efficiency and accuracy in coding.
  • Note-making platform Evernote kotlinized their Android app for further clarity in development and to reduce vulnerabilities.
  • Food delivery giant Zomato opted for Kotlin to make their Android app fail-safe and render a better user experience.
  • Project collaboration tools like Trello is deployed upon Kotlin for scalability and continuously adding new features.
  • Geosocial networking platform Tinder uses Kotlin in its code architecture for its concise syntaxes.

Companies that use Kotlin


The main functionality of Groovy is observed in scripting. As part of the Apache JMeter distribution, Groovy’s usage in scripting is comparatively more impactful. Its utility has also been reported in the following examples—

  • Video streaming giant Netflix uses Groovy codes for scripting on the server side to attain high performance and scalability.
  • Business and HR platform LinkedIn uses Grails framework for recruiters and developed Glu— deployment and monitoring platform. Both are developed using Groovy.
  • American tech giant Oracle’s Fusion Middleware, software facilitating development and service-oriented architecture (SOA) management, uses Groovy for scripting.
  • Groovy is also used by multinational companies like Starbucks and finance firms like MasterCard.

Companies that use Groovy

Kotlin vs Groovy — syntax


The syntaxes in Kotlin are condensed and focused on accuracy. This helps developers gain profound insight while programming and improves productivity. In addition, one of the major advantages of Kotlin over other languages, including Java, is null safety. In that, there are two notations: nullable and non-nullable types. This feature not only prevents runtime errors but also assists developers in promptly fixing references.

Furthermore, as previously mentioned, Kotlin also provides other exceptional features including smart type casting, fail-safe mechanism, type-safe builders, and excellent integrated development environment (IDE) support.


Similar to Kotlin, Groovy’s syntaxes are also compact and aren’t much different from Java. In Groovy 1.8, a new annotation @Canonical was introduced to carry out AST transformations through a single execution. It can be combined with @ToString, @EqualsAndHashCode, and @TupleConstructor to create mutable classes. This, basically, shortens the code blocks for classes.

Another notable Groovy feature is Groovy Closure. These are blocks of codes assigned to variables to process arguments and output a value. The advantage here is that Closure can be added with variables that are free and undefined in the given set.

Kotlin vs Groovy — compiling


Kotlin was developed as a statically typed programming language. This was to remove redundancies and boilerplate codes. But it also signifies that the variable types are checked at the compile time. Compile time type checking allows expressive language features, performance optimization, and enhanced IDE support.


Groovy has the characteristics of both a statically typed and dynamically typed language. The dynamic type setting is applicable as default. Implying that the variables are checked at run-time. To enable the static typesetting, either @CompileStatic annotation can be deployed, or the configuration file can be specified in the compiler.

Kotlin vs Groovy — code style settings


JetBrains opted to keep code configuration in Kotlin limited. The code styles, while incredibly capable, do not facilitate customization. It prevents code formatting distinct from what’s offered in IntelliJ on the IDE.


On matters of code style configuration, Groovy offers better flexibility than Kotlin but lags behind Java. However, developers have preferred consistency between the functional style and the imperative style.

Kotlin vs Groovy — performance

When it comes to performance, Kotlin is strides ahead of Groovy and matches the ability of Java. Groovy’s case is such owing to more runtime checks. Groovy closures also impact performance and are significantly slower in processing variables.

The dynamic character of Groovy prevents the compiler from assessing the object type whether to retrieve property or call a method. This is mostly done when the variable types are compiled during the runtime. Since there is no possible way to predefine methods and their implementation, Groovy’s performance is significantly lower. Another critical reason for such a characteristic of Groovy is to ensure interoperability with Java.

Kotlin vs Groovy comparison

What is better Between Groovy vs Kotlin for Android app development?

Traditionally, the preferred language for Android apps has been Java. But after Google’s declaration of Kotlin as the official language for Android, it has picked up wider acceptance amongst developers. On the other hand, Groovy is predominantly favored for scripting and simplified testing.

Exclusively for Android application development, Kotlin has already become the go-to programming language. There’s also a promising future ahead for Kotlin since it’s backed by Google. Therefore, mastering Kotlin if a developer wishes to build Android applications, can be considered.

How Appventurez Can Power Your Android App Development Project

Whether the preferred programming language is Kotlin or Groovy for your Android app development project, the foremost requirement is an excellent, affordable, and trustable partner. At Appventurez, we transform exceptional ideas into exceptional products. 

Essentially as an Android app development company, we follow a client-centric approach. The production environment runs on a critically developed business strategy that values market trends and customer preferences. All this while guaranteeing on-time delivery, post-production monitoring, and continuous client support.

Android app development


Q. Which of Groovy and Kotlin is the better Android app development programming language?

Strictly for Android app development, a large segment of developers around the world prefer Kotlin. However, when it comes to scripting and testing, Groovy is the option to go with. Kotlin also takes the lead on the scale of performance optimization, consistency, lesser vulnerabilities, and backing by Google. 

Q. Are Kotlin app developers in high demand?

Yes! Owing to the simplified and concise code syntaxes and a simpler learning curve, the demand for Kotlin has been rising. This received further impetus after backing from Google. For developers already adept in Java, it is even easier to learn and switch to Kotlin.

Q. What are the core differences between Kotlin and Groovy?

The essential difference between Kotlin and Groovy is in compiling. While both are executable on JVM, Kotlin is statically typed and the variable is checked during compile time. Whereas, Groovy is predominantly dynamic typed but can also be executed as static type, and the type checking is done in run-time.


CTO at Appventurez

CTO and Co-Founder at Appventurez, Sitaram Sharma has 10+ years of experience in providing world-class digital solutions. As a CTO, he brought his expertise ranging from product enhancements to advanced technological integrations, while focusing on the consistent growth of the team.

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