Kotlin vs Swift: Which language is better for mobile app development? Our comprehensive guide covers the key differences in syntax, performance, and popularity to help you decide.
In this modern era of computing and constant connection, consumers, customers and clients depend on mobile applications to make it easier to interact with your company, purchase your products, obtain information about a service and even help promote your business. Across the world, the most popular mobile platforms are Android and iOS. This means comparing Kotlin and Swift, the two most popular programming languages for Android and iOS (respectively).
Although the popularity of these two operating systems varies from region to region, there is no escaping the fact that your company must consider one or the other (or even both) to remain competitive in a very complex and growing market. Ultimately, this means you must consider your market before selecting which language would best suit your business.
Before you decide, however, you might want to know a little more about these two languages. Let's delve deeper into both.
What is Kotlin?
At one point, Java ruled Android development. While this has barely changed, there is another language that has quickly become popular among Google and Android developers around the world. That language is Kotlin. And while Java is still heavily used in the development of the Android operating system itself, on May 7, 2019, Google announced that Kotlin would become the de facto standard for Android app development.
Kotlin emerged in July 2011. Dmitry Jemerov (lead developer at JetBrains) realized that most languages (with the exception of Scala) didn't include the features he needed. And although Scala included the desired features, it was very slow in compiling the code. Jemerov and JetBrains decided to create a language that had the features of Scala and the compile time of Java.
In February 2012, JetBrains open-sourced the new language under the Apache 2 license, naming it Kotlin, a name inspired by Kotlin Island, similar to how Java was named after the Indonesian island.
At the moment, Kotlin's TIOBE Index is 35, while Java's is 3, so clearly Java is still much more popular than Kotlin. However, this does not mean that you will have trouble finding a Kotlin development company anywhere in the world. And as Android development continues to flourish, so does Kotlin.
Advantages/Pros of Kotlin
Kotlin has a number of very important advantages over other languages used to develop Android applications. These advantages include the following:
- Less is more – With Kotlin, you will write less code. JetBrains has done a great job of creating a very concise language. And because you'll write less code, you'll introduce fewer bugs.
- Written by those in the industry – Instead of being created in academia, Kotlin was created by those already in the industry, so they created a language that solved many challenges faced by developers.
- Easy to learn and adopt – Kotlin was created to be easy to use and adopt. And because Kotlin easily integrates (and is fully compatible) with Java, you can make it work with your existing code.
- Zero Runtime Overhead – The Kotlin standard library is designed to be lean and fast and primarily serves as an extension to the Java standard library.
- Cross-platform development – Not only can you use Kotlin for Android development, but it also integrates seamlessly with JavaScript, so you can easily migrate your front-end apps to Kotlin with little effort.
- No Null References – British computer scientist Sir Tony Hoare once referred to the null reference as “the billion-dollar mistake.” Kotlin's type system virtually eliminates null references.
Disadvantages/Cons of Kotlin
Although Kotlin has many advantages, it includes some important disadvantages to note, such as:
- Fewer tools – Unlike Java, Kotlin doesn't have nearly the same number of third-party tools available.
- Slower compilations – Although the goal was to create a language that could compile as quickly as Java, Kotlin does not meet that mark.
- Smaller community – You will find Kotlin developers all over the world, but they are not as numerous as other languages at the top of the TIOBE index.
Which companies use Kotlin?
There are many companies using Kotlin today, including the following:
- Udemy
- Day off
- Robinhood
- BELIEVE
- Delivery Hero
- Technology Stack
- Flammable
- HENNGE KK
- Postmates
- Uber
- Evernote
- Course
Which Android app development tools integrate with Kotlin?
While you won't find as many tools for Kotlin as you would for Java, there are still some important tools to keep in mind, such as:
What is the Swift programming language?
As Kotlin is the official language for Android app development, Swift is the official language for iOS app development. Swift is a high-level, general-purpose programming language that was initially created in July 2010 by Chris Lattner. Eventually, several Apple programmers were added to the development of Swift.
Swift incorporated features from languages such as Objective-C, Rust, Haskell, Ruby, Python, C# and CLU. It wasn't until June 2, 2014, at the Apple Worldwide Developers Conference, that Swift Apple released the first app built with Swift (which was the official WWDC app). Soon after that, a beta version of Swift was released by Apple.
Currently, Swift has a TIOBE index of 20, which makes it more popular than Kotlin but much less popular than Java. But because many important markets are dominated by iOS devices, it's very easy to find and hire a Swift development service to help your company build and launch apps for the Apple ecosystem.
Advantages/Pros of Swift
There are many advantages to adopting Swift, such as:
- iOS App Development – If you want to develop iOS apps, you have two options, Objective-C and Swift.
- Easy to learn – Unlike Objective-C, Swift is considerably easier to learn.
- Rapid development – Apple claims that developing with Swift is 2.6 times faster than developing with Objective-C.
- Simple syntax and readability – Swift was created with the idea of creating a language with simple syntax and readability, which means code maintenance is considerably easier.
Disadvantages/Cons of Swift
Swift is not just advantages. Take these cons seriously when making your choice:
- A young language – Swift is not as mature as many other languages. And while it's fully supported by Apple, you may find that the community and support tools aren't what you're used to.
- Backwards Compatibility – Swift suffers from some backwards compatibility issues. With each new version of the language, previous versions are not compatible.
- Limited – Swift is largely limited to development for MacOS, iOS, iPadOS, Apple TV and Apple Watch.
Which companies use Swift?
Given the popularity of Apple products, you can be sure that many companies use Swift these days, including:
- Uber
- Lyft
- Airbnb
- Asana
- door panel
Which mobile app development tools integrate with Swift?
There are many tools available to Swift developers to help simplify development efforts, such as:
Main differences between Kotlin and Swift
| Kotlin | Fast | |
|---|---|---|
| Year of Creation | 2011 | 2014 |
| The creator | JetBrains | Apple Inc. |
| Documentation | Kotlin Docs | Swift Docs |
| Language type | Compiled Language | Compiled Language |
| Typing | Statically typed | Statically typed |
| TIOBE Classification | 26 | 18 |
| Popularity | Growing Fast (StackOverflow Research) | Growing Fast (StackOverflow Research) |
| Forms | Android app development, backend development, web development | iOS, macOS, watchOS, tvOS, server-side development |
| Performance | Comparable | Comparable |
| Stability | Stable | Stable |
| Learning curve | Moderate – Beginner-friendly syntax and great tool support | Moderate – beginner-friendly syntax and Xcode IDE |
| Community support | Several popular online learning resources | Several popular online learning resources |
| Development time | Generally shorter than some other languages | Generally shorter than some other languages |
| Main advantages |
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| Main disadvantages |
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| Famous Companies | JetBrains, Uber, Trello, Atlassian, Coursera, Pinterest | Apple Inc., IBM, LinkedIn, Lyft, Slack, Airbnb, many startups |
| Cross-platform support | Kotlin Multiplatform (KMP) | Swift (with limited support for Linux and Windows) |
There are some important differences between Kotlin and Swift that you should consider when choosing software development services, such as the following:
- Android vs iOS – Kotlin is used to develop Android apps and Swift is used to develop iOS apps.
- Data Classes – While Kotlin includes data classes (a way for developers to store data), Swift does not.
- Underscore – While Swift makes use of underscore in variables as a prefix, Kotlin does not.
- Extensions – Swift allows extensions to add additional functionality, but Kotlin does not.
- Error Handling – In Kotlin, errors are indicated with null whereas Swift uses nil.
What will the future be like
There is no doubt that both Kotlin and Swift will continue to dominate mobile app development. Although Android and iOS apps can be developed in different languages (Java for Android and Objective-C for iOS), Kotlin and Swift are easier to use and will therefore continue to grow in popularity.
Kotlin versus Swift: who wins?
It depends on the market. For example, in the US and Japan, iOS is the dominant mobile platform; So, if you are a startup looking to establish yourself in one app ecosystem or another, iOS and Swift are the best choice. However, if you're looking at India, where Android is much more popular than iOS, the choice is simple.
If, however, you want to develop an application for global use, you will probably want to adopt both languages.
When to use Kotlin
The choice is simple. If you want to develop an Android app, choose Kotlin.
When to use Swift
Again, the choice is quite simple. If your company is more focused on developing and releasing apps for the Apple ecosystem (iOS, MacOS, iPadOS, Apple TV, and Apple Watch), your only choice between the two would be Swift.
Source: BairesDev
