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Top 10 Best Cross Platform App Development Frameworks in 2021

Top 10 Best Cross Platform App Development Frameworks in 2021

These top 10 best cross-platform app development frameworks in 2021 help app developers with code reusability, better ROI, easy maintenance and shorter time to market.

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With the rapid advancements in technology in today’s highly competitive digital sphere, developers are continuously on a hunt for app development tools or frameworks that can make their job easier and minimize app development time and cost. 

Consequently, now in 2021, you will see that an overwhelming amount of cross-platform app development frameworks have emerged to bridge that demand. The increased frequency of search queries can be seen by looking at Google trends’ indicators from 2009 to date.

What is a Cross-Platform App Development Framework?

A cross-platform app development framework is a set of tools that allows you to build native or native-like apps for multiple platforms such as Android, iOS, Windows and Web with a single codebase. 

This enables you to expand your reach to a much larger target audience on multiple platforms at a significantly reduced cost and less time.

Here are some of the best open-source cross platform app development frameworks based on programming languages:

 
Programming Language Framework
Java
Codename One
JavaScript
React Native, Cordova, Ionic, NativeScript, Appcelerator
Python
Kivy, BeeWare
C#
Xamarin
C++
Qt
Ruby
RubyMotion
Dart
Flutter
Basic
B4A

Is Cross Platform better than Native Development?

Cross-platform vs Native development is a never-ending debate that has kept the tech community divided for many years. Both technologies are in a constant state of evolution. However, as platforms converge, the future seems to be more in favor of cross-platform. 

To give you an overview, let’s look at the comparison between native and cross-platform across various important factors.

Factors Native App Development Cross-Platform App Development
Architecture
Different apps for different platforms
One app for multiple platforms
Cost
High cost of development
Relatively low cost of development
Code Reusability
Almost none, code works for a single platform
Single code can be used on multiple platforms, for an easy portability
Hardware Access
Complete hardware accessibility with platform SDKs
Limited access to all device APIs
UI/UX
Consistent & platform specific UI/UX
Unified UI/UX for all platforms with limited consistency
Performance
Seamless, fully native performance
High performance, native-like
Target Audience
Limited to a specific platform
Reach a large number of users
Time to Market
More time required as need to write different code
Significantly reduced time to market due to single codebase
Team Size
Large (different resources for different platforms)
Small (1 for all platforms)

What are the Benefits of Cross-Platform App Development Frameworks?

Here are some of the upsides of cross-platform app development frameworks.

Code Reusability

Possibly the biggest upside of cross-platform app development frameworks is code reusability. Developers just need to code once and that codebase can be reused to deploy the app to multiple platforms. This concept is commonly referred to as “Write Once Run Anywhere” or WORA.

WORA eliminates repetition, and in turn, saves operational costs. A shared codebase also allows you to add another platform at a later point without too much effort.

Reduced Costs & Resources

Cross-platform app development frameworks help you find a good balance between quality and cost by allowing you to be agile while utilizing a smaller team with one skill set and codebase for multiple platforms. 

It’s simple math: Less time, resources, and efforts spent on app development is directly proportional to lower costs.

Easy Deployment & Maintenance

Since there’s a single codebase for multiple platforms, developers only need to write and maintain just a single source code. This translates to easy and fast deployment, maintenance, updates, and bug fixes.

When updates are made to the code, they are synced over multiple platforms and devices instantly, saving time and effort.

Wider Market Reach

Cross-platform frameworks give you maximum exposure to your target audience by allowing you to deploy your app on multiple platforms i.e. Android, iOS, Windows, MacOS, Web etc. This ensures a wider market reach to potential users. 

Uniform Design

Cross-platform frameworks make it easier to share a unified UI/UX across different platforms, while still respecting platform-specific standards. Offering users a consistent experience will help them easily recognize and interact with the app on any platform.

Benefits of Cross-Platform App Development Frameworks

Top 10 Best Cross-Platform App Development Frameworks in 2021

There are many cross-platform app development frameworks out there, having their own pros and cons.

However, there’s NO one size fits all framework for cross-platform app development. Everything comes down to your preferred programming language and the platforms you want to target.

Choosing the right tool can be a daunting task. We have tried our best to be as unbiased as possible while making this list of the top 10 best cross-platform app development frameworks in 2021.

Cross-Platform Frameworks Based on Programming Languages

Following parameters were considered while putting this list together:

  • – Performance & popularity
  • – Code reusability
  • – Plugins, integrations & components
  • – Ease of learning 
  • – Community support & documentation
  • – Ability to access device capabilities

1. React Native

Launched in 2015, React Native is Facebook’s open-source cross-platform mobile app development framework. It uses JavaScript and React.js libraries to build apps for Android, iOS, Mac, Windows and the Web.

React Native is based on Facebook’s JavaScript library React, which renders to native platform UI. React Native is a great choice for simple apps where the APIs have a clear bridge between platforms. However, for complex apps, native code is often needed to bridge any gaps in functionality.

The Stack Overflow Developer Survey Results 2019 listed React Native in the category of dreaded frameworks for the first time.

Programming Language: JavaScript

Famous Apps: Facebook, Bloomberg, Walmart, Uber and Shopify.

Avg. App Development Cost: The average cost of React Native app development ranges from $15 to $25 per hour.

Recommended Course: The Complete React Native + Hooks Course ($95)

Architecture: The following diagram shows a high-level view of the React Native application architecture.

React Native architecture
React Native Pros React Native Cons
React Native's focus on UI is to a great extent, rendering a highly responsive interface.
React Native is not a truly cross-platform framework. Code is not 100% reusable across platforms, depending on the app’s complexity.
Rich variety of built-in and community driven components and APIs save development time.
When it comes to releasing of updates, React Native lacks consistency.
Fast Refresh feature enables developers to see changes made in code within seconds.
React Native apps are not efficiently optimized for speed and memory use.
React Native is supported by contributions from developers and companies around the world. It has one of the highest number of contributors for any repository in GitHub.
React Native's dependency on third-party libraries is on the higher side.

2. Xamarin

Launched in 2011 and acquired by Microsoft in 2016, Xamarin is an open-source cross-platform app development framework that uses C# language, .Net framework and Visual Studio to build apps for Android, iOS, macOS, and Windows (UWP).

Xamarin offers great compile-time checking which allows developers to experience fewer run-time errors. Xamarin also makes it easy to design a native-like app with its native friendly interface and controls assisting.

Xamarin integrates with Visual Studio which is a Microsoft’s IDE for the .NET Framework, allowing Visual Studio to be used for creating applications for Android, iOS and Windows.

Programming Language: C#

Famous Apps: UPS, Alaska Airlines, Microsoft News and BBC Good Food.

Avg. App Development Cost: The average cost of Xamarin developers ranges from $20 to $50+ per hour.

Recommended Course: The Complete Xamarin Developer Course: iOS And Android!

Architecture: The following diagram shows a high-level view of the Xamarin application architecture.

Xamarin architecture
Xamarin Pros Xamarin Cons
Allows sharing up to 90% of your code across platforms for “Write Once, Run Anywhere”.
Depending on complexity, Xamarin apps are typically larger in size than native ones.
Platform-specific UI elements with Xamarin.Forms delivers consistent look across different OS.
Xamarin is not recommended for apps that demand rich graphics. A UX/UI-heavy app is advised to be implemented natively.
Xamarin supports linking with native libraries and uses platform-specific APIs.
Xamarin has limited access to certain important open source libraries.
Xamarin has a strong community of over 60,000 contributors from more than 3,700 companies.
Xamarin is free for individuals and startups. However, enterprises are required to buy a license for Microsoft’s Visual Studio.

3. Codename One

Created by the co-founders of the LWUIT project in 2012, Codename One is the leading open source Write Once Run Anywhere (WORA) framework to build native apps for iOS, Android, Desktop and Web with Java or Kotlin.

Codename One is a revolutionary mobile development solution started by ex-Sun Microsystems developers based on the work that started within Sun.

Its core appeal is its unrestricted access to the native platform allowing developers to write native code directly from Java or Kotlin and access everything that the native mobile platform can provide.

Related: Codename One comparison with other frameworks

Programming Language: Java or Kotlin

Apps made with Codename One: Muving, yHomework, HBZ, CIPC, Oxbridge Academy & Hyundai Smart Care.

Avg. App Development Cost: The average cost of Java developers ranges from $30 to $60 per hour.

Recommended Course: Codename One Academy (Free & Paid courses)

Architecture: The following diagram shows a high-level view of the Codename One application architecture.

Codename One architecture
Codename One Pros Codename One Cons
Write Once Run Anywhere (WORA) support with no special hardware requirements and 100% code reuse.
Not suitable for elaborate games such as FPS. The framework and related tools were designed from the start focused around apps.
Codename One has plugins for popular IDEs such as IntelliJ/IDEA, NetBeans and Eclipse.
Codename One's graphic UI does not match the requirements of large projects and its visual themes are not updated.
Codename One is easy to use with 100% portable Drag & Drop GUI builder.
Due to the storage of all event handlers in a single file, development part is cumbersome.
Codename One can be extended easily using 3rd party libraries (cn1libs) that can include native OS code.
While it's possible to build without the cloud build server, in case if its needed, then there's a monthly quota of builds.
Codename One’s cloud build allows developers to build native applications using cloud servers. This removes the need to own dedicated hardware.

4. Flutter

Developed and released by Google in 2017, Flutter is a popular open source and free cross-platform framework. It uses Dart language to develop apps for Android, iOS, Mac, Windows, Linux and the Web from a single codebase.

Flutter has a strong following in the cross-platform community as its a versatile SDK for mobile app development. The Stack Overflow developer survey 2020 results suggests that Flutter is the third-most loved framework.

Flutter framework, as well as Dart language, hasn’t been around for long, which is why it’s still not entirely stable and mature. 

Programming Language: Dart

Famous Flutter Apps: Google, eBay, Alibaba and BMW

Avg. App Development Cost: The average cost of Flutter app development ranges from around $15 to $50 per hour.

Recommended Course: Flutter & Dart – The Complete Guide ($131)

Architecture: The following diagram shows a high-level view of the Flutter application architecture.

Flutter architecture
Flutter Pros Flutter Cons
Flutter is easy to learn, simple to build and debug with, and is fully compiled.
Dart is a less popular programming language and the Hot Reload feature works only with Dart.
Flutter has a full set of widgets in Google’s Material Design and in Apple’s style with the Cupertino pack.
Flutter doesn't support all the devices. It won't run on your 32-bit laptop seamlessly.
Hot Reload feature enables developers to see changes made in code within seconds.
There are fewer third-party packages available to support Flutter apps on multiple platforms.
Flutter's community of developers is active and evolving, proactively helping developers in solving problems related to the platform.
Flutter is suitable for MVP and startups. For large-scale projects, you will have to proceed smartly.
Flutter is relatively new and growing. You will find little proven expertise in the market.
Flutter apps are relatively bigger in size.

5. Ionic

Released in 2013, Ionic open-source framework leverages web technologies such as HTML, CSS, and JavaScript with integrations for frameworks such as Angular, React and Vue to build hybrid mobile, desktop, and Progressive Web Apps.

Ionic framework uses a SaaS UI and is fundamentally built on Cordova. It uses Cordova and Capacitor plugins to gain access to native OS features such as Camera, GPS, Flashlight, etc.

Ionic has its own IDE known as Ionic Studio. Ionic also offers features such as code deploys, automated builds, lazy loading, Ionic CLI, etc.

Programming Languages/Frameworks: JavaScript, Angular, React and Vue.js

Famous Apps: NHS, EA Games and Southwest Airlines.

Avg. App Development Cost: The average cost of Web or AngularJS developers ranges from $25 to $150+ per hour.

Recommended Course: Ionic – Build iOS, Android & Web Apps with Ionic & Angular

Architecture: The following diagram shows a high-level view of the Ionic application architecture.

Ionic architecture
Ionic Pros Ionic Cons
Based on well-known technologies i.e. Angular, HTML, CSS and JavaScript.
If one wants to go beyond basic apps, knowledge of AngularJS becomes almost a necessity.
Compatability with React, Angular and Vue frameworks and supports Cordova plugins.
Performance of apps built with Ionic is on a lower side.
Ionic has a wide range of tools, plugins and UI components.
Building in-app navigation is difficult because of its complex UI-router.
Ionic is backed by a vibrant community of developers and sufficient documentation.
High dependency on plugins. Some native plugins aren't stable and can conflict with each other.

6. Cordova

Apache Cordova (formerly PhoneGap) is an open source framework that utilizes HTML, CSS, and JavaScript to build hybrid web apps for Android, iOS and Windows.

Apache Cordova is the open source fork of the PhoneGap project which was acquired by Adobe in 2011. Adobe later discontinued PhoneGap in 2020.

Apps built with Cordova are hybrid, meaning that they are neither truly native nor purely Web-based. Cordova enables wrapping up of HTML, CSS and JavaScript depending upon the platform of the device.

Cordova apps rely on standards-compliant API bindings to access each device’s capabilities such as data, sensors, network status, etc.

Programming Language: HTML, CSS & JavaScript.

Famous Apps: Pacifica, Sworekit, FanReact & JustWatch.

Avg. App Development Cost: The average cost of Web developers ranges from $30 to $80+ per hour.

Recommended Course: Apache Cordova Fundamentals

Architecture: The following diagram shows a high-level view of the Cordova application architecture.

Cordova architecture
Cordova Pros Cordova Cons
Based on well-known technologies i.e. HTML, CSS and JavaScript.
Cordova apps are slower than native mobile apps due to the cross-compilation process.
Compatible with a variety of third-party plugins and APIs. Also supports custom plugins.
Developers find it daunting to find plugins based on their precise needs.
The command line syntax is easy to learn and implement.
Not recommended for high-performance and hardware intensive apps due to poor performance and lack of UI Widgets.
Easy to setup, develop, adding platforms and deploying apps for multiple platforms.
Supporting different devices can become very difficult.

7. NativeScript

Released in 2015, NativeScript is an open-source framework that allows you to build native Android and iOS apps using JavaScript, TypeScript, Angular or Vue.js.

NativeScript allows developers to access native Android and iOS APIs and render platform-native UI. While the app source code is written in web languages, NativeScript apps run directly on the native device without using WebViews or DOM manipulation.

NativeScript’s major components include Runtimes, Core Modules, CLI and Plugins. The Runtimes call the native APIs using JavaScript. Core Modules provide abstractions to access native platforms. The CLI allows to create, build, and run apps using NativeScript. And the Plugins form the building blocks of NativeScripts for faster development. 

Programming Languages/Frameworks: JavaScript, TypeScript, Angular and Vue.js

Famous Apps: Strudel, BitPoints,  Daily Nanny & Dwitch.

Avg. App Development Cost: The average cost of NativeScript specialists ranges from $40 to $120+ per hour.

Recommended Course: NativeScripting (Free & Paid courses)

Architecture: The following diagram shows a high-level view of the NativeScript application architecture.

NativeScript architecture
NativeScript Pros NativeScript Cons
Based on well-known web technologies i.e. JavaScript, TypeScript, Angular and Vue.js
NativeScript is not a truly cross-platform framework. Code is not 100% reusable across platforms, depending on the app’s complexity.
Gives access to native Android and iOS APIs.
NativeScript runs everything on a single thread which can lead to the apps feeling slower.
Renders platform-native UI without relying on WebViews.
No hot-reload feature to preview instant code changes without an app restart.
Large repository of plugins and pre-built app templates.
The app size could be reduced to be more in line with pure native and other similar frameworks.
NativeScript is 100% free and open source.
Due to the many different ways you can write NativeScript apps, the documentation is not always accurate.

8. Appcelerator Titanium

Released in 2008, Appcelerator Titanium is an open-source cross-platform native app development framework for building iOS, Android and Windows apps with JavaScript.

The core features of Titanium SDK includes a cross-platform API for accessing native UI and device functionality, direct access to native APIs using Hyperloop and MVC-based framework Alloy.

Appcelerator offers pre-built integrations with Salesforce, MS Azure, MS SQL, MongoDB and Box. It also offers ArrowDB, a schema-less database that allows developers to deploy data models with no setup efforts.

Programming Language: JavaScript.

Famous Apps: Body Shop, CBC Media, MIT & Pulse.

Avg. App Development Cost: The average cost of Appcelerator Titanium specialists ranges from $40 to $70+ per hour.

Recommended Course: Beginner Mobile App Development with Appcelerator Titanium

Architecture: The following diagram shows a high-level view of the Appcelerator Titanium application architecture.

Appcelerator Titanium architecture
Appcelerator Titanium Pros Appcelerator Titanium Cons
JavaScript compiles to native code with no hybrid compromises.
Limited code reusability (60-90%) across platforms.
Direct access to native APIs using Hyperloop.
The development complexities and costs rise as app complexity increases.
Access to native UI across platforms with Alloy.
Appcelertor Titanium often requires that you rewrite your UI (roughly 50% of the code) for every platform.
Schema-less ArrowDB with no setup efforts.
Titanium apps are often slower and laggy with animations and responsiveness.
Growing community of developers.
Errors are usually not detected until runtime.

9. Qt

Released in 1995, Qt is an open-source widget toolkit for creating cross-platform apps and GUIs for Android, iOS, Windows, macOS, Linux and embedded systems using C++.

Qt is used for developing cross-platform apps and graphical user interfaces (GUIs) that run on most mobile, desktop or embedded platforms. Qt supports compilers such as Visual Studio, GCC compiler and PHP via an extension. 

Qt tools include the Qt Creator IDE for C++ and Qt Quick which includes a declarative scripting language called QML. Other Qt features include XML parsing, JSON parsing, SQL database access and thread management. 

Programming Language: C++.

Qt use cases: Spotify, Malwarebytes, VLC Player, Google Earth etc.

Avg. App Development Cost: The average cost of Qt developers ranges from $30 to $70+ per hour.

Recommended Course: Qt 5 Core for Beginners with C++

Architecture: The following diagram shows a high-level view of the Qt application architecture.

Qt architecture
Qt Pros Qt Cons
Qt is mature and stable. It has been vetted by major companies.
The time to market is long without using Qt Quick Compiler, which is only available with the Commercial license.
It is a well-designed C++ GUI application framework.
Mobile UX is far from being smooth. When using default QT GUI components you do not get an ideal look and feel for iOS and Android.
The code is compiled to native binaries that run at full speed (no need to use a virtual machine)
There is no official Qt support for mainstream Ad Networks (only 3rd party libraries, if available)
Qt's IDE, Qt Creator is very capable and works on all platforms.
QT requires licensing fees for distribution. If you stop paying the monthly licensing fee, you need to stop distributing the apps you’ve already built.
Qt has huge user base and documentation. It's easy to get answers to questions.
The QObject and QWidget are not thread-safe.

10. RubyMotion

Released in 2012, RubyMotion is a partially open-source framework for creating cross-platform native apps for Android, iOS and MacOS using Ruby.

Ruby programming language is mainly used for web development. However, with RubyMotion, mobile apps can be made using Ruby. 

RubyMotion is based on MacRuby, an implementation of Ruby created and maintained previously at Apple. RubyMotion adapted and extended MacRuby to work on platforms beyond MacOS.

Apps written in RubyMotion call into the native platform APIs and function in the same manner as platform native language. RubyMotion apps are created from the terminal command-line using any text editor.

Programming Language: Ruby.

Apps made with RubyMotion: A Dark Room, Jimdo, Bandcamp, Jukely & Frontback.

Avg. App Development Cost: The average cost of Ruby developers ranges from $30 to $80+ per hour.

Recommended Course: Getting Started with RubyMotion

Architecture: The following diagram shows a high-level view of the RubyMotion application architecture.

RubyMotion architecture
RubyMotion Pros RubyMotion Cons
Ruby as a language for mobile development environment.
RubyMotion is not open-source. It's a commercial partially open-source product.
RubyMotion apps are statically compiled and call into the native platform APIs.
RubyMotion requires separate GUI code for Android and iOS.
RubyMotion apps can be extended with Gems (reusable components).
It's hard debug with RubyMotion.
CocoaPods and Gradle are supported natively.
RubyMotion's free version is limited.
Terminal + Editor of choice workflow.
RubyMotion needs better documentation for beginners.

Frequently Asked Questions (FAQs)

A cross-platform app development framework is a set of tools that allows you to use a single codebase to build native or native-like apps for multiple platforms such as Android, iOS, Desktop and Web.

Choosing the right cross-platform framework comes down to your preferred programming language and the platforms you want to target. There’s NO one size fits all framework for cross-platform app development. 

There is no one best programming language for cross-platform development. Which language to use for a particular app depends on the type of app, development team, and the specific project requirements.

 

Programming languages such as Java, C++ and JavaScript are widely considered preferred languages for cross-platform app development.

Benefits of cross-platform app development includes:

 

1. Code Reusability

2. Reduced Costs & Resources

3. Easy Deployment & Maintenance

4. Wider Market Reach

5. Uniform Design

Disadvantages of cross-platform app development includes:

 

1. Performance issues

2. Difficult to build an optimal UI/UX

3. Limited access to hardware

4. Long wait time for new features

5. Code losses if switching to another platform

Cross-platform app development is less costly as compared to native app development since there's a single codebase, they're quicker to develop and take less QA effort.

 

Cross-platform apps usually cost $30 to $80+ per hour depending on the requirements and complexity.

Compared to native apps, cross-platform apps take less time to develop and deploy since there’s only a single codebase for multiple platforms that developers need to write and maintain.

 

The development time of cross-platform apps depends on several factors such as the complexity, target platforms and technical skills.

Final Thoughts

Cross-platform app development is the obvious route if you’re looking for code reusability, budget savings, easy maintenance and quick deployment as opposed to native development.

Cross-platform development also makes your code simpler and faster to read, write, maintain, debug, re-use and scale.

When choosing the best cross-platform app development framework, there’s NO one size fits all tool. What’s the best framework for you really depends on your technical skills, preferred programming language, project requirements and the platforms you want to target.

3 Comments

  • Francesco Galgani says:

    I thank you for this very interesting article.
    The document included in an iframe (Google trends’ indicators) is not visible.
    It’s very nice to find this overview about cross platform tools right on Codename One blog.

    The discussion on the pros and cons could be expanded, but the considerations would still be subjective and related to their own development experience. Certainly, Codename One allows with few resources and few people to do what otherwise would require many more resources and many more people.

  • Vitali Kuptsov says:

    Thank you for your article! I wouldn’t be sure for Cordova as imo it’s not as great as it used to be due to new frameworks that really surpass it. For example, Flutter which you also mentioned. Flutter definitely wins with its HotReload and automated testing, and more native UI. I’ve read about it recently in this article [link removed], and it looks quite convincing.

    • Shai Almog says:

      I removed your link since it appears to be SEO related. FYI Codename One supports hit reload etc. This isn’t such a unique feature.

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