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Tuukka Turu

Building Blocks of Modern Web Development – Web Components

The rapid pace of web development demands continuous innovation and efficiency. Developers are actively seeking new ways to streamline their workflow and enhance user experience. A significant step forward has been the emergence of web components. These compact and versatile elements offer developers a fresh approach to building web applications and a powerful toolkit for creating modular and maintainable user interfaces.

What are web components?

At their core, web components are a set of standardized technologies that enable developers to define their own HTML elements. Comprising three main technologies – Custom Elements, Shadow DOM, and HTML Templates – web components allow for the creation of encapsulated, reusable components that can be seamlessly integrated into almost any web application.

How are web components created?

At its simplest, custom elements can be created with Vanilla JavaScript. However, this is not the most efficient or appealing way to create components. Fortunately, there are libraries available that enable an efficient and user-friendly way to create components.

Lit.dev, supported by Google, is gaining popularity and offers an excellent starting point for developing your own components. StencilJS, developed by the Ionic organization, is another library for web component development.

Where can web components be used?

Web components can be used in many different contexts, from simple websites to complex single-page applications (SPAs). They are particularly useful in situations where modular, reusable elements are needed across different parts of an application or when building component libraries for widespread use.

Web components and design systems

Design systems have gained popularity among larger organizations, where the need for a consistent visual style across multiple services is important. Web components offer an ideal tool for their implementation.

Design systems are a collection of defined components, styles, and guidelines that enable a consistent appearance and behavior across all parts of an application.

Web components fit naturally into design systems, offering clear, modular, and easily reusable building blocks that support the correct visual style and, most importantly, are functional and accessible elements. In this way, they promote consistency and efficient design implementation in different use cases. Additionally, the use of web components allows for effortless updating and maintenance of components, making design systems more dynamic and flexible.

Why use web components?

There are several compelling reasons to adopt web components in modern web development:

  • Reusability: Web components enable the creation of reusable elements, reducing unnecessary repetition and promoting code efficiency.
  • Modularity: Encapsulating functionality in separate components allows for greater modularity, making code management and maintenance easier.
  • Compatibility: Web components are compatible with different framework and library environments, offering flexibility and compatibility in various development contexts.
  • Encapsulation: Shadow DOM ensures encapsulation, preventing style and behavior conflicts between components and the surrounding page.
  • Standardization: As a W3C standard, web components enjoy broad support in modern browsers, ensuring consistency and reliability in web development projects.

What challenges might arise?

While web components offer numerous advantages, they also come with challenges:

  • Browser support: Although support for web components is extensive, older browsers may lack full compatibility, requiring polyfills or alternative arrangements.
  • Complexity: Developing and managing web components can be complex, especially for teams not yet fully familiar with the technology.
  • Performance load: Depending on implementation, web components can cause performance load, particularly in large component counts.
  • Potential SEO challenges: Depending on the implementation approach, SEO can be a challenge. Search engine crawlers may have difficulty reading Shadow DOM elements, as they require JavaScript processing. However, this challenge can often be resolved, for example, through server-side rendering if the application architecture allows it.

Advantages and Disadvantages of Web Components


  • Reusability and modularity promote code efficiency.
  • Compatibility ensures application functionality across different framework and library environments.
  • Encapsulation prevents style and behavior conflicts.
  • Standardization promotes consistency and reliability.


  • Browser support may vary, requiring polyfills or alternative arrangements.
  • Development and management can be complex, especially for beginners.
  • Performance at the browser level can pose challenges in extensive setups.

This is a concise, high-level overview of web components. In the next part, we will delve deeper and examine the more technical side.


Tuukka Turu

Front-end Developer