Mastering Flutter Performance Optimization: A Comprehensive Guide to Best Practices

Last updated on April 2nd, 2024

Introduction

Flutter is an open-source mobile application development framework created by Google. It allows developers to build high-quality, native-like applications for Android, iOS and other platforms using a single codebase. With its fast development cycle and beautiful user interfaces, Flutter has gained immense popularity among developers.

However, with great power comes great responsibility. As the complexity of a Flutter app increases, so does its performance overhead. As a developer, it is crucial to understand how to optimize the app’s performance to provide a smooth and enjoyable user experience. In this guide, we will explore various techniques and best practices for optimizing Flutter app performance.

Flutter Performance Optimization Tips

Ignore Rebuilding of Widget Tree

One of the significant advantages of Flutter is its reactive widget model, where any changes in the state result in rebuilding only the widgets affected by that change. However, sometimes this can be a double-edged sword. While it improves performance in most cases, there are also instances when it can cause unnecessary rebuilding and decrease app performance.

To optimize performance in such cases, we can use the `const` constructor for stateless widgets and `key` property for stateful widgets. The `const` constructor creates a widget that is immutable and will not rebuild unless necessary, while the `key` property allows us to control when a widget needs to be rebuilt.

Also Read: Can Existing Native App Code Be Converted to Dart for Flutter?

Prefer Async/Await over Futures

Futures are a fundamental concept in Dart for managing asynchronous code. While they are powerful, using multiple `await` calls within a future can introduce performance challenges. Each `await` call triggers the creation of a new microtask queue, which can lead to unnecessary overhead.

To enhance application performance, an alternative approach involves combining the `async` and `await` keywords. By using these together, developers can structure asynchronous code in a more synchronous manner. This not only streamlines the code but also reduces the proliferation of microtask queues, resulting in an overall improvement in performance.

Reduce the Size of the App

The size of the app can significantly impact its performance, particularly in cases where the user’s device has limited storage or resources. Therefore, it is crucial to consider ways to reduce the app’s overall size.

One approach is to eliminate unused resources and dependencies from the project. We can use tools such as `flutter clean` and `flutter pub get –offline` to delete any unnecessary files and dependencies, respectively. Another method is to use libraries like `flutter_lints` to identify unused resources in the codebase.

Terminate utilized resources

When working with resources in Flutter, such as files or databases, it is essential to ensure that these resources are properly closed and terminated once they are no longer needed. Failing to do so can result in performance issues and potential memory leaks.

To alleviate this issue, we should use the `dispose()` method of the `State` class. This method is called when stateful widgets are removed from the widget tree, providing an opportunity to close any open resources.

In addition, it is also crucial to ensure that streams and subscriptions are canceled when they are no longer needed. This can be achieved by using the `cancel()` method on the stream or subscription object.

Minimize resources imported from libraries

The use of external libraries can greatly enhance the functionality of an app, but it can also increase its size and potentially impact performance. Therefore, it is essential to be mindful of the resources being imported from these libraries.

To minimize this impact, we should only import the necessary resources from a library instead of importing the entire package. This can be achieved by using `as`, `show`, and `hide` keywords when importing, which allows for selective importing of specific resources.

In addition, we should regularly review the libraries being used in our project and remove any that are no longer needed. This can help reduce the overall size of the app and improve its performance.

Create And Portray Frames Within 16ms

One of the main goals of developing apps in Flutter is to provide a smooth and responsive user experience. To achieve this, it is crucial to ensure that frames are created and portrayed within 16ms.

Frames refer to individual instances of rendering a single frame on the screen. By keeping the creation and portrayal of frames within 16ms, we can achieve a constant frame rate of 60 frames per second, which is considered the gold standard for smooth animation and user interactions.

To achieve this, we can follow some best practices such as using `setState()` only when necessary to update the UI and avoiding unnecessary calculations or operations in the build method. Additionally, we can use tools like Flutter’s Performance Overlay and Timeline to identify any performance issues and optimize our code accordingly.

Sidestep Utilizing ListView For Longer Lists

ListView is a commonly used widget in Flutter for creating lists with scrollable content. However, it is recommended to avoid using ListView for longer lists as it can significantly impact performance.

Instead, we should use the `ListView.builder` constructor, which only renders items that are currently visible on the screen. This method uses less memory and improves performance by avoiding rendering all list items at once. Additionally, we can also use the `ListView.separated` constructor to separate items with dividers or headers, without impacting performance.

Ignore Build Method Calls For Unchanged Widgets

The build method is triggered whenever changes in the widget tree require a rebuild. This frequent rebuilding can potentially lead to redundant widget rendering, adversely affecting our application’s performance. To counter this issue, a strategy involves leveraging the `const` keyword for widgets that remain static and don’t necessitate rebuilding, like unchanging text or icons. By implementing this approach, the application can be optimized, reducing the need for repeated calls to the build method for unaffected widgets and enhancing overall efficiency.

Use Const Keyword For Stateless Widgets

Stateless widgets in Flutter, known for their immutability, maintain fixed properties post-construction. This immutability feature aligns perfectly with the `const` keyword, ensuring these widgets preserve their initial state through rebuilds. To introduce a state change, const constructors can be combined with conditional statements for optimized rendering. This meticulous approach guarantees a balance of stability and flexibility within the Flutter framework, enhancing the development process.

Read More: Flutter App Development Cost 

What Else Can We Do for Better Performance of Flutter App?

Apart from the techniques mentioned above, there are other ways we can improve the performance of our Flutter app:

Describing the Architecture of the Flutter App

Having a clearly defined architecture for your Flutter application is crucial for optimizing its performance. The implementation of well-thought-out architectural patterns like MVC (Model-View-Controller), MVP (Model-View-Presenter), and MVVM (Model-View-ViewModel) plays a vital role in structuring the codebase effectively. This not only enhances efficiency but also ensures maintainability in the long term. By adopting these architectural patterns, you establish a strong foundation for organizing your code, which helps in separating concerns and results in a more robust and scalable Flutter application. This meticulous structuring leads to improved readability, easier maintenance, and streamlined development processes, ultimately contributing to the overall success of your Flutter project.

Make a Pure Build function

The build function in Flutter is a cornerstone of app development, serving a crucial role in seamlessly rendering widgets on the screen. Within this function, prioritizing purity by ensuring it exclusively returns a widget, free from any side effects, is vital. This emphasis on purity lays the foundation for enhanced performance and efficiency within the app.

To uphold this purity, a strategic approach involves extracting logic into separate functions or classes rather than embedding them directly into the build method. By adopting this practice, not only is the code structure streamlined, but unnecessary rebuilds are minimized, leading to an overall boost in application performance and responsiveness. This meticulous attention to detail in separating concerns contributes to maintaining a clean and efficient codebase that can adapt to evolving user demands and technological advancements.

Write Tests for Critical Functionalities

One of the most significant advantages of Flutter is its ability to write tests for user interfaces, improving code quality and minimizing errors. By writing tests for crucial functionalities, you can effectively establish a robust safety net that ensures your app functions as expected throughout the development process.

In addition to having an error-free application, testing also serves as an efficient debugging tool, helping identify any potential bugs or issues before they cause significant problems. Furthermore, by leveraging the popular testing framework – Flutter Driver, developers can perform integration tests that more closely simulate user interactions with the app, resulting in a comprehensive evaluation of an application’s overall performance.

Use Streams Only When it is Mandated

Streams are an essential part of Flutter’s reactive architecture, enabling developers to efficiently handle asynchronous data streams. However, overusing this feature may lead to performance issues due to unnecessary resource consumption. Therefore, it is crucial to use streams only when necessary and consider alternative methods like FutureBuilder or Stateful Widgets for situations where streams are not mandatory.

Nonetheless, when used correctly, streams can be remarkably beneficial in managing state changes and updating the UI accordingly. Moreover, by utilizing an efficient error handling mechanism, developers can minimize errors and address them more effectively, ensuring a smoother user experience.

Make Utilize of the State Management Packages

State management is an essential aspect of app development that can be challenging to handle, especially with large and complex applications. Fortunately, there are numerous state management packages available for Flutter, such as Provider, Bloc, MobX, and many more. These packages offer different approaches to managing state in a Flutter application and provide developers with a structured way to handle data flow.

By utilising these state management packages, developers can keep their code organized and easily manage complex state changes. Moreover, it helps in maintaining the scalability and performance of an application by avoiding unnecessary rebuilds and optimizing resource consumption.

How can iTechnolabs help you to build a flutter application?

At iTechnolabs, we pride ourselves on our dedicated team of experienced Flutter developers. These experts are well-versed in utilizing the latest technologies and industry best practices to craft robust and efficient applications tailored to your specific needs.

Our developers excel in leveraging streams, state management packages, and other advanced features of Flutter to ensure the creation of high-quality, user-friendly apps that align perfectly with your business requirements.

Additionally, our commitment to a streamlined development process guarantees not only timely delivery but also cost-effective solutions for your projects. Embracing an agile development approach, we actively involve our clients at every stage of the process, ensuring that the final product not only meets but exceeds their expectations.

• Expert Team: iTechnolabs prides itself on housing a team of dedicated Flutter developers with vast experience and a profound understanding of Flutter and its intricacies. This ensures that your app is meticulously crafted using the most up-to-date technologies and industry best practices, guaranteeing a top-tier end product.
• Tailored Solutions: Our forte lies in crafting bespoke applications tailored precisely to your unique business requirements. This bespoke approach ensures that your app not only meets but surpasses market expectations, setting your business apart from the competition.
• State Management Proficiency: Our adept developers excel in a wide array of state management techniques and packages. This proficiency empowers us to develop sophisticated, high-performance applications with seamless data flow and impeccable organization, enhancing user experience and functionality.
• Agile Methodology: Embracing an agile development methodology, we prioritize client collaboration at every phase of the development lifecycle. From initial planning to final deployment, our agile approach ensures transparent communication, timely feedback incorporation, and flexible project delivery, meeting evolving project needs efficiently.
• Cost-Effective Solutions: Our optimized development process not only ensures punctual project delivery but also offers cost-effective solutions without compromising quality. This commitment enables you to maximize the return on your investment, receiving exceptional value within your budget constraints.
• Quality Assurance: Quality and performance are paramount at iTechnolabs. Leveraging the advanced features of Flutter, we place a strong focus on delivering high-quality, user-centric applications that not only meet but exceed your expectations, ensuring your app stands out in today’s competitive market landscape.

Are you planning to Hire dedicated Flutter developers?

Choosing iTechnolabs for your Flutter application optimization offers a multitude of benefits that can significantly elevate the performance and appeal of your app. Our expertise in custom application development allows us to tailor optimization strategies that align perfectly with your specific business needs, ensuring an efficient, high-performing application. With our state management proficiency, applications we optimize are guaranteed to deliver a smooth, intuitive user experience, thanks to well-organized data flow and impeccable state management. Additionally, our agile methodology facilitates a collaborative and flexible optimization process, allowing for adaptive enhancements in line with evolving market trends and customer feedback. This approach not only speeds up the optimization process but also ensures that the final product is of the highest quality and tailored to the market demands. Lastly, our commitment to providing cost-effective solutions means that you get the best value for your investment, enhancing not just the app’s performance but also its market competitiveness without straining your budget.

• Expert Flutter Development Team: iTechnolabs prides itself on having a dedicated team of experienced and proficient Flutter developers. Our experts not only stay updated with the latest trends and technologies in app development but also bring a wealth of knowledge and skill to the table, ensuring that your app is crafted using cutting-edge practices tailored to your specific needs.
• Customizable and Scalable Solutions: When you choose iTechnolabs for your Flutter app development, you gain access to fully customizable solutions that are designed to be scalable, adapting seamlessly to the growth of your business. Our tailored services are meticulously crafted to meet your unique business requirements, offering flexibility and agility to support your long-term goals.
• UI/UX Design Excellence: At iTechnolabs, our dedicated design team is committed to delivering excellence in UI/UX design. We focus on creating visually appealing and intuitive interfaces that prioritize user experience. By keeping engagement and usability at the forefront of our design process, we ensure that your users have a seamless and enjoyable interaction with your app.
• Comprehensive Testing and Quality Assurance: Quality is at the core of our app development process. Before your app is launched, it undergoes a series of rigorous tests to identify and resolve any issues. Our thorough testing protocols ensure that your app performs flawlessly across various devices and platforms, providing a reliable and consistent user experience.
• Post-Launch Support and Maintenance: Our commitment to your success extends beyond the development phase. iTechnolabs offers comprehensive post-launch support and maintenance services to keep your Flutter app running smoothly. We provide ongoing updates, feature enhancements, and security measures to ensure that your app remains up-to-date and continues to deliver value to your users.

Important: How to Convert Your Existing Mobile App to Flutter Quickly?

Conclusion: 

At iTechnolabs, we understand that every business has unique needs and goals. That’s why our Flutter app development services are tailored to meet your specific requirements, offering a fully customizable and scalable solution for your business. With our focus on UI/UX design excellence, comprehensive testing and quality assurance, and post-launch support and maintenance, we are dedicated to helping you create a successful and user-friendly app that stands out in the competitive market. Trust us to bring your vision to life and take your business to the next level with our Flutter app development services.