Blazor vs. React—key differences, pros and cons, and use cases

Blazor vs. React—architecture and language diversity

Developing a Blazor app—C# and Razor

Blazor allows developers to write web applications using the C# programming language and Razor syntax, which is a templating language that combines HTML and C# code. Blazor uses a component-based architecture where each component is a reusable piece of UI logic that can render HTML, handle user events, and communicate with other components. Some of the advantages of using C# and Razor are:

• C# is a mature, powerful, and expressive programming language that supports object-oriented, functional, and asynchronous programming paradigms.
• Razor provides a concise and intuitive way to mix HTML and C# code, with features such as tag helpers, partial views, and directives.
• Blazor is compatible with the .NET ecosystem, which means that developers can leverage existing libraries, tools, and frameworks, such as ASP.NET Core, Visual Studio, and Azure.

React: JavaScript and JSX

React is a library that helps developers create user interfaces using JavaScript and JSX, which is a syntax extension that allows developers to write HTML-like code in JavaScript. React uses a declarative approach where developers specify how the UI should look based on the state of the application. React also uses a virtual DOM, which is a lightweight representation of the real DOM that enables fast updates and rendering.

Some of the advantages of using JavaScript and JSX are:

• JavaScript is a versatile, dynamic, and widely used programming language that runs on all browsers and platforms.
• JSX provides a familiar and expressive way to write HTML in JavaScript, with features such as custom components, props, states, hooks, and life cycle methods.
• React is compatible with existing web technologies, such as HTML, CSS, SVG, and web APIs. It also has a large and active community that provides many libraries, tools, and JS frameworks such as Redux, Next.js, or Material UI.

Blazor vs. React—component model

Blazor and React both use a component-based approach to create reusable, interactive UI elements. Let us take a closer look at the component model of Blazor and React, focusing on component structure and life cycle, data binding, and event handling.

Developing a Blazor app—components and Razor syntax

Blazor components are .NET classes that inherit from the ComponentBase class and have a. razor file extension. They use Razor syntax, which is a combination of HTML and C#, to define the UI markup and logic. Blazor components support data binding and event handling using C# expressions and directives. Data binding allows the UI to reflect the state of the component, and event handling allows the component to respond to user actions.

Blazor components have a life cycle that consists of several methods that are invoked at different stages of rendering and updating the UI. This means that each component goes through specific stages that include creation, initialization, updating, and disposal. Each of them has its own life cycle methods that are called as needed.

React—components and JSX

React components are JavaScript functions or classes that accept input data and return JSX (a syntax extension that looks like HTML) elements that describe the UI. The JSX syntax is a combination of HTML and JavaScript used to define the UI markup and logic.

React components have a life cycle that consists of several methods that are invoked at different stages of mounting, updating, and unmounting the UI. React components support data binding and event handling using JavaScript expressions and props (input data). Unlike Blazor, React does not support two-way data binding by default, but it can be achieved using third-party libraries such as Redux.

Blazor vs. React—state management

Both Blazor and React have various ways to manage the state of the components and the data flow in the application. In either of them it is possible to use both native and third-party solutions.

Developing a Blazor app—state management solutions

Blazor has two hosting models: server-side and client-side. In server-side Blazor, the state of the components is maintained on the server and updated via SignalR. In client-side Blazor, the state of the components is maintained on the browser and updated via JavaScript.

The built-in solutions for state management in Blazor include: CascadingValue, which can provide a value to all its descendants without using parameters; and EventCallback, which can be used to trigger a UI update on the parent component when something changes on the child component.

Third-party solutions for state management in Blazor include: Fluxor, which is a library that implements the Flux (a unidirectional data flow architecture) pattern; and Blazor-State, another library, which implements the Mediator (a behavioral design pattern that defines an object that encapsulates how a set of objects interact) pattern for Blazor apps.

React—state management solutions

React uses a virtual DOM to render components and update them efficiently when the state changes. It has two types of components: class components and function components. The former have a state object that can be updated using the setState method, while the latter have hooks that can be used to add states and other features.

The built-in solutions for state management in React include: useState—a hook that allows you to add a local state variable to a function component; useEffect—a hook that allows you to synchronize a component with an external system; and useContext—a hook that allows you to access data from a context object, which can provide a value to all its descendants without using props.

The third-party solutions for state management in React include: Redux—a library that implements the aforementioned Flux pattern for React and has three principles: a single source of truth, state is read-only, and changes are made with pure functions; and MobX, which is a library that implements reactive programming, a paradigm that deals with data streams and propagation of change.

Blazor vs. React—performance

For obvious reasons, performance can be the make or break for modern web apps and app builders. So, let us look at Blazor and React from that perspective.

Developing a Blazor app—WebAssembly and server-side rendering

WebAssembly, which allows developers to write C# code that runs in the browser, is a binary format that can be executed by the browser at near-native speed. This means that Blazor can leverage the power of the .NET framework and C# without relying on JavaScript or plugins. WebAssembly can run complex computations faster than JavaScript, which can improve the user experience and responsiveness of the web app.

However, WebAssembly also has some limitations, such as the size of the downloaded files, the app startup time, and compatibility with older browsers. To compensate for these issues, Blazor Server offers a server-side rendering mode, where the C# code runs on the server and UI updates are sent to the browser using SignalR. Blazor Server apps can reduce the download size and improve compatibility with modern web browsers, but it also introduces some latency and dependency on the network connection.

Blazor apps—optimization

To optimize the performance of Blazor apps, developers use some of the following techniques:

• Ahead-of-Time (AOT) compilation—to reduce the download size and startup time of WebAssembly apps.
• Lazy loading—to defer loading of some assemblies until they are needed.
• Prerendering—to render the initial UI on the server and send it to the browser as static HTML.
• Caching and compression—to reduce the network bandwidth and latency.
• Component virtualization—to render only the visible items in a list or grid.

React—virtual DOM and client-side rendering

React uses a concept called virtual DOM, which is an in-memory representation of the real DOM. React compares the virtual DOM with the previous state and updates only the changed parts in the real DOM. This allows React to avoid unnecessary re-rendering and improves the performance of the web app. It can enable fast and easy UI updates without affecting the state or logic of the app.

However, virtual DOM also has some drawbacks, such as the memory overhead, the complexity of debugging, and the potential for performance bottlenecks. Like Blazor, React also offers a server-side rendering mode to compensate for some of the problems. This can improve SEO and initial loading time for the client-side applications and web app, but it also requires additional configuration and synchronization between the server and client.

React app—optimization

There are a few ways to make good React applications. As far as optimization goes, here are some of the techniques that can be used:

• Code splitting, to divide the app into smaller chunks that can be loaded on demand.
• Hydration, to attach event listeners to the static HTML rendered by the server.
• Memoization, to speed up the render process by caching and reusing the results of expensive function calls.
• Hooks or custom components, to avoid unnecessary re-rendering or state updates.

Blazor vs. React—ecosystem and community

Both frameworks have a rich ecosystem of libraries, tooling, and community support that can help developers build their applications faster and easier.

Developing a Blazor application—libraries, tooling, and community support

There are a number of open-source tools for popular libraries and extensions for Blazor, such as Blazorise (provides Bootstrap, Bulma, Ant Design, and Material UI components), MatBlazor (implements Material Design components), Blazored (a collection of libraries that provide various functionalities), and Fluxor (implements the Flux/Redux pattern for state management). Developers working with Blazor can also use tools such as Visual Studio (the official IDE for developing Blazor applications), Visual Studio Code, or the Blazor WebAssembly Debugging Extension.

Other than the official Blazor documentation, developers also have access to community resources such as Awesome Blazor (a curated list of libraries, tutorials, samples, videos, podcasts, etc.) and Blazor University (an unofficial documentation website). There is also, obviously, copious information on Stack Overflow and Reddit.

React—libraries, tooling, and community support

Some of the popular libraries and extensions for React include:

• Redux, which implements the Flux/Redux pattern for state management;
• Create React App, which sets up a modern React project with no configuration;
• React Router—a JavaScript framework that allows you to handle client and server-side routing in React applications;
• Material UI (MUI)—a component library that features the implementation of Google’s Material Design system.
• Bootstrap—an open-source frontend toolkit that contains HTML, CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components;
• Tailwind—an open-source CSS library providing a list of utility CSS classes that can be used to style each element.

Aside from Chrome DevTools—the official developer tools for Chrome that support debugging React applications in the browser—developers working on React app development can use tools such as Create React App (a CLI tool that sets up a project with no configuration) and React Developer Tools (another Chrome extension).

They can also refer to the official documentation or Awesome React—a curated list of resources on GitHub.

Blazor vs. React—learning curve

Blazor is a framework that allows developers to write web applications using C# and HTML. Therefore, for developers who already have experience with these languages, it can be a natural choice for web development, as they can leverage their existing skills and knowledge and use familiar tools such as Visual Studio and NuGet. Furthermore, existing .NET libraries and components can be reused in Blazor applications.

React, on the other hand, allows developers to write web applications using JavaScript and JSX, so it benefits from the large and vibrant JavaScript community, which provides a lot of resources and libraries for various scenarios. React can also offer a smooth learning curve for developers who already have experience with JavaScript. They can use their existing skills and knowledge and familiar tools such as VS. Code and npm, as well as the many available JavaScript libraries and components.