Swift vs. Flutter: Which One to Choose for Your iOS App Development


Most of the business has achieved a lot of opportunities with the help of mobile apps. In the past few years, mobile app development has been experiencing an increase in demand and is expected to reach $189 billion by the end of 2020. This is mainly due to the increase in demand for mobile applications for e-Commerce, entertainment, and gaming.

When it comes to launching a mobile app, most entrepreneurs prefer launching apps on Android and iOS platforms, as this is where almost all users are. Many businesses are often confused between Android app development or iOS app development for their first app. Choosing the platform is based on your business requirements and your goals. If you are someone targeting users in the USA, getting an app developed for iOS platforms is a great idea, as most people use iPhones here.

Now that we are done with deciding the platform, the next step is to choose the right mobile app framework for your app development. There are a number of frameworks available in the market but choosing the right one can get a bit difficult. Most app development companies prefer using either Swift or Flutter for creating native iOS apps.

So, to make things clearer and help you make the right decision. Here, in this article, we will compare Swift vs. Flutter, so that you can choose the perfect framework for iOS app development. Before starting the comparison let us have a brief idea about both, Flutter and Swift framework.

More about: Swift

Swift is one of the most popular programming languages developed by Apple for iOS, iPadOS, macOS, watchOS, tvOS, and Linux. One of the most striking features of this language is that it constantly evolves with changing trends and demands. Swift is one of the most preferred languages among iOS developers and also, Swift app development is high in demand for the amazing features it adds to the application.

Swift has exceptional tools, frameworks, and documentation to work with natives easily. It is a fast-paced, type-paced, and dynamic programming language which is continuously being developed and accompanying value additions. Swift may eventually replace Objective-C scripting language for iOS app development.

More about: Flutter

Developed by Google, Flutter is known to create beautiful looking natively compiled apps for both Android and iOS operating systems, using a single codebase. It uses Dart language to provide robust documentation.

Flutter is packed with benefits like hot reload feature; integrated & Cupertino (iOS-flavour) Widgets & Material Components; default animation library, rich 2D GPU-accelerated APIs; rapid speed development; compliance with design standards; use of Google’s Fuchsia OS and is efficient for cross-platform mobile development.

Swift vs. Flutter– Comparing the Features

Every iOS app has unique features, technologies, and frameworks used inside. Therefore, there is no point to create a complex app for comparison. Let’s look over the main differences in the mobile app development between Flutter and Swift. However, it is important to build an identical app using both technologies so that we can justify the points of differences.

Here is a listicle of the features on which we are going to compare these two languages.

  1. Speed
  2. Reloading features
  3. Onboarding process
  4. Testing and Documentation
  5. Profiling
  6. Accessibility
  7. App Size
  8. Development Time

Let’s discuss these points of comparison in detail, to have a clear understanding of both, Swift and Flutter.


Speed is the basic check as with app development, it is necessary to control its development time and cost. Hence, you have to select the appropriate coding language.


It is the fastest language in today’s programming language and is mostly compared with the speed of C language. You can easily measure the build time using the codebuild command-line tool or Xcode.


It is comparatively slower than Swift but as one goes beyond initial clean builds, it gets faster. For Flutter iOS development alongside Xcode, you should install Flutter binary also.

Reloading Features

The codes of any app are changed frequently for updates or tests on the device or simulator. The testing procedure is essential to add for mobile app development in the form of app reloading. When app developers make some changes in the code, they test the result on devices, and this process is called reloading.


In case you need to change the button name, you require renaming the element from the storyboard which possibly needs changes in data and accessibility. It needs to rebuild the application to check if it is working on the devices. In Xcode, this procedure takes 7 to 12 seconds.


Flutter framework’s “hot reload” feature allows you to quickly reload the code on a running app. After the code files run into Virtual Machine, Flutter automatically reflects the updated widgets on the app screen and allows you to view the changes.

Onboarding Process

Swift is a platform to develop native iOS apps, but Flutter utilizes Dart programming language. Hence, both programs need a different setup for on boarding.


Native tools are used to set up iOS app development and use Xcode as the IDE, the fundamental development kit incorporated in Xcode. Once Xcode is installed on the macOS, we can create a new iOS project in Xcode by selecting File> New > Project > iOS > Single View App. We can then name this app and select Swift as the language. It is less complicated and much easier.


Flutter iOS development is a bit different since it requires a Flutter binary. Along with this, IntelliJ IDEA and Android Studio is preferable while setting it up. Once the setup procedure is done, the Flutter app development command can come handy such as native-compare.

Testing and Documentation

Testing is the main feature of any mobile app development. Most companies have a separate team of quality analysts who scrutinizes your app for any errors. Flutter and Swift both have a lot of variations while comparing the testing and documentation.


Apple provides XCTest, which is a robust framework for native testing of tasks like UI testing, integration testing, and performance testing. Though it lacks features like snapshot tools and data-driven testing.


When it comes to testing in Flutter, a robust testing system is in place. It acts as an invaluable promise from Flutter. It helps test writing right from the UI level to the functional level. It also helps the developer in writing the tests even from the unit level, and there is a Flutter driver that runs all the tests successfully. It is an accurate testing system that is robust and great for fast-paced documentation.


It helps analyze CPU, resources, memory, and other functionality factors of the application.


From Xcode, we have the option to profile an app using Product > Profile. This will launch an instrument app where we can analyze the app by different criteria. Once you launch the Time Profiler, you can start recording and select the button many times.


In Flutter, you can profile iOS applications with the IDE or from the command line. The Flutter build time for profiling is approximately 149 seconds. To run profile apps from the command line, the following command need to be followed:-

$ flutter build ios –profile –no-codesign


Every mobile app development company needs to make the app accessible so that the services can reach a maximum number of people.


Swift iOS tools have accessibility in the UIKit framework. So, there is no requirement of importing any third-party framework for allowing accessibility support in Swift apps.


Flutter documentation recommends measuring iOS apps by using the Accessibility inspector tool of Xcode. Flutter iOS apps don’t have any mature support to add accessibility. Flutter needs to make improvements.

App Size

It’s time to compare the size of both apps generated by the native Xcode and Flutter.


The app is in the .app format. The binary size of the native apps made of swift is around 23.2 MB.


It usually generates the directory named build/ios/Debugiphonesimulator. The app size can go up to 52.4 MB that is bigger due to the assets and app icons.

Development Time

Digging into every app and analyzing the development time for both, Swift and Flutter platform, are equally important after establishing the app.


The build time of native iOS apps can be easily measured with Xcode or the xcodebuild command-line tool by running the following command.

$ defaults write com.apple.dt.Xcode ShowBuildOperationDuration -bool


There are sets of guidelines that one has to follow to develop the app via the Flutter platform. We can build the Flutter apps just for iOS in debug mode using the following command.

$ flutter build ios –debug –no-codesign –simulator

Final Words

Swift is the most common and viable option for most iOS app development companies. However, Flutter has greater speed and complexity, supporting different platforms with the same source code. As a result of the comparison, it seems that native iOS development has some significant advantages over Flutter and gets a higher score in this comparison. Undoubtedly, Flutter offers cross-platform support but Swift is still better for building all things iOS.

In future Flutter may overtake the Swift in terms of iOS app development. Flutter apps look very close to native apps and there is a big opportunity for Flutter to grow in the future to offer competition to the native tools. Also, it is good for Android apps. Though Swift is considered as a faster one as one goes beyond initial clean builds, flutter gets faster. In the years to come, we can expect Flutter to be more accessible, while Swift is still dominating the iOS app development.