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Apple recently announced a new declarative UI framework for its operating system – SwiftUI, at its annual developer conference WWDC 2019. SwiftUI will power all of Apple’s devices (MacBooks, watches, tv’s, iPads and smartphones). You can integrate SwiftUI views with objects from the UIKit, AppKit, and WatchKit frameworks to take further advantage of platform-specific functionality. It’s said to be productive for developers and would save effort while writing codes.

SwiftUI documentation,  states that, “Declare the content and layout for any state of your view. SwiftUI knows when that state changes, and updates your view’s rendering to match.”  

This means that the developers simply have to describe the current UI state to the response of events and leave the in-between transitions to the framework. The UI updates the state automatically as it changes.

Benefits of a Declarative UI language

Without describing the control flow, the declarative UI language expresses the logic of computation. You describe what elements you need and how they would look like without having to worry about its exact position and its visual style.

Some of the benefits of Declarative UI language are:

  • Increased speed of development.
  • Seamless integration between designers and coders.
  • Forces separation between logic and presentation.   
  • Changes in UI don’t require recompilation

SwiftUI’s declarative syntax is quite similar to Google’s Flutter which also runs on declarative UI programming. Flutter contains beautiful widgets with captivating logos, fonts, and expressive style. The use of Flutter has significantly increased in 2019 and is among the fastest developing skills in the developer community.

Similar to Flutter, SwiftUI provides layout structure, controls, and views for the application’s user interface. This is the first time Apple’s stepping up to the declarative UI programming and has described SwiftUI as a modern way to declare user interfaces. In the imperative method, developers had to manually construct a fully functional UI entity and later change it using methods and setters. In SwiftUI the application layout just needs to be described once, vastly reducing the code complexity.

Apart from declarative UI, SwiftUI also features Xcode, which contains software development tools and is an integrated development environment for the OS.  If any code modifications are made inside Xcode, developers now can preview the codes in real-time and tweak parameters. Swift UI also features dark mode, drag and drop building tools by Xcode and interface layout.  Languages such as Hebrew and Arabic are also incorporated.

However, one of the drawbacks of SwiftUI is that it will only support apps that will continue to relay forward with iOS13. It’s a sort of limited tool in this sense and the production would take at least a year or two if an older iOS version is to be supported.

SwiftUI vs Flutter Development  

Apple’s answer to Google is simple here. Flutter is compatible with both Android and iOS whereas SwiftUI is a new member of Apple’s ecosystem. Developers use Flutter for cross-platform apps with a single codebase. It highlights that Flutter is pushing other languages to adopt its simplistic way of developing UI.

Now with the introduction of SwiftUI, which works on the same mechanism as Flutter, Apple has announced itself to the world of declarative UI programming. What does it mean for developers who build exclusively for iOS? Well, now they can make Native Apps for their client’s who do not prefer the Flutter way. SwiftUI will probably reduce the incentive for Apple-only developers to adopt Flutter.

Many have pointed out that Apple has just introduced a new framework for essentially the same UI experience. We have to wait and see what Swift UI has under its closet for the longer run.

Developers in communities like Reddit and others are actively sharing their thoughts on the recent arrival of SwiftUI. Many agree on the fact that “SwiftUI is flutter with no Android support”.  

Developers who’d target “Apple only platform” through SwiftUI, will eventually return to Flutter to target all other platforms, which makes Flutter could benefit from SwiftUI and not the other way round.

The popularity of the react native is no brainer. Native mobile app development for iOS and Android is always high on cost and companies usually work with 2 different sets of teams. Cross-platform solutions drastically bridge the gaps in terms of developmental costs. One could think of Flutter as React native with the full support of native features (one doesn’t have to depend on native platforms for solutions and Flutter renders similar performance to native).

Like React Native, Flutter uses reactive-style views. However, while React Native transpiles to native widgets, Flutter compiles all the way to native code.


SwiftUI is about making development interactive, faster and easier. The latest inbuilt graphical UI design tool allows designers to assemble a user interface without having to write any code. Once the code is modified, it instantly appears in the visual design tool. Codes can be assembled, redefined and tested in real time with previews that could run on a range of Apple’s devices. However, SwiftUI is still under development and will take its time to mature.

On the other hand, Flutter app development services continue to deliver scalable solutions for startups/enterprises. Building native apps are not cheap and Flutter with the same feel of native provides cost-effective services. It still remains a competitive cross-platform network with or without SwiftUI’s presence.

Author Bio

keval padia

Keval Padia is the CEO of Nimblechapps, a prominent Mobile app development company based in India. He has a good knowledge of Mobile App Design and User Experience Design. He follows different tech blogs and current updates of the field lure him to express his views and thoughts on certain topics.