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Jakub Andrzejewski
Jakub Andrzejewski

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Understanding Vue’s Virtual DOM

Vue.js is a progressive JavaScript framework that offers a reactive and efficient way to build user interfaces. One of the key components that contribute to its performance and responsiveness is the Virtual DOM.

In this article, we'll explore how Vue’s Virtual DOM works can help optimize your applications and write more efficient code.

Enjoy!

🤔 What is the Virtual DOM?

The Virtual DOM (VDOM) is an abstraction of the real DOM. Instead of directly manipulating the actual DOM, Vue creates a lightweight copy of it in memory. This virtual representation allows Vue to perform efficient updates by determining the minimal number of changes needed before applying them to the real DOM.

Vue render pipeline
Source: https://vuejs.org/guide/extras/rendering-mechanism

Vue’s Virtual DOM operates through a series of steps:

  1. Rendering: When a Vue component renders, a Virtual DOM tree is created using JavaScript objects that describe the UI structure.
  2. Diffing Algorithm: When a component’s state changes, Vue creates a new Virtual DOM tree and compares it with the previous version. The framework uses a diffing algorithm to identify the differences between the two trees.
  3. Patching Process: After identifying the changes, Vue applies only the necessary updates to the real DOM through a process called patching. This minimizes re-renders and improves performance.

🟢 Benefits of Using Vue’s Virtual DOM and how we can optimize it?

Using Vue's Virtual DOM comes with many benefits such as:

  1. Performance Optimization: Since updates are calculated in memory before applying changes to the actual DOM, Vue minimizes unnecessary reflows and repaints, making applications more efficient.
  2. Improved Developer Experience: The declarative nature of Vue’s rendering process allows developers to focus on state management and UI logic without worrying about manual DOM manipulation.
  3. Cross-Platform Compatibility: The Virtual DOM enables Vue to work seamlessly across different environments, including mobile frameworks like Weex and NativeScript.

Although Vue’s Virtual DOM is optimized by default, developers can take additional steps to ensure their applications run efficiently:

  • Use Keyed v-for Lists: Adding a unique key when rendering lists helps Vue track changes more efficiently.
  • Lazy Loading and Code Splitting: Load components only when needed to reduce initial load time.
  • Avoid Unnecessary Component Re-renders: Use computed properties and watchers strategically to prevent excessive reactivity updates.
  • Use Functional Components: For stateless components, functional components offer improved performance as they don’t have an instance of their own.

📖 Learn more

If you would like to learn more about Vue, Nuxt, JavaScript or other useful technologies, checkout VueSchool by clicking this link or by clicking the image below:

Vue School Link

It covers most important concepts while building modern Vue or Nuxt applications that can help you in your daily work or side projects 😉

✅ Summary

Vue’s Virtual DOM is a powerful mechanism that improves performance and optimizes UI updates. By understanding how it works and implementing best practices, you can build efficient, high-performing Vue applications.

Take care and see you next time!

And happy coding as always 🖥️

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Top comments (4)

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jisan profile image
Jisan Mia

Amazing! I just found out about your wonderful series on Vue, @jacobandrewsky .
I've worked with React extensively in my previous projects. Now, in my current company, we use Vue.js, and this series of yours about Vue could not be more helpful!

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jacobandrewsky profile image
Jakub Andrzejewski

I am pretty happy that it helps you! If you will see any areas that you would like to read an article about, let me know :)

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gabrielgomeso profile image
Gabriel Gomes de Oliveira

Great article! Is there a way to reduce the DOM while loading/building the page (for performance improvements) and then progressively bring back the skipped content afterward? I’m looking for something that isn’t exactly like server components or Nuxt Islands but achieves a similar effect. Any thoughts?

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jacobandrewsky profile image
Jakub Andrzejewski

Hey, thanks for the kind words!

I am not sure if I understand correctly, but maybe Lazy Hydration could help here? :)

👋 Kindness is contagious

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