Modern web development offers many JavaScript frameworks and libraries for building fast, interactive user interfaces. React, Vue, Angular, and Svelte are some of the most popular choices, but another technology gaining attention among frontend developers is SolidJS.

SolidJS is a modern JavaScript library designed for building highly reactive and performant web applications. At first glance, its syntax can look similar to React, especially because it uses JSX. However, SolidJS works very differently behind the scenes.

Instead of relying on a Virtual DOM and repeatedly re-rendering components, SolidJS uses fine-grained reactivity to update only the exact parts of the interface that have changed.

In this beginner’s guide, we will understand what SolidJS is, how it works, its major features, signals, components, installation process, advantages, limitations, and when you should consider using it.

---

What Is SolidJS?

SolidJS is a declarative JavaScript library for building fast and reactive user interfaces.

It allows developers to create reusable UI components using JavaScript and JSX.

A simple SolidJS component might look like this:

function Welcome() {
  return <h1>Hello, SolidJS!</h1>;
}

export default Welcome;

If you have worked with React before, this syntax will look familiar.

However, the internal architecture is significantly different.

SolidJS does not use a traditional Virtual DOM. Instead, it compiles templates and connects reactive data directly to the DOM elements that depend on that data.

This approach helps SolidJS perform updates efficiently.

---

Why Was SolidJS Created?

Modern applications frequently contain dynamic data.

For example, an application may need to update:

• counters
• notifications
• search results
• shopping carts
• dashboards
• user profiles
• form values
• real-time messages

Whenever application data changes, the user interface needs to reflect that change.

Different frontend technologies solve this problem differently.

React commonly uses state changes followed by component rendering and Virtual DOM reconciliation.

SolidJS takes another approach.

It tracks the relationships between reactive values and the UI. When a reactive value changes, SolidJS can update the specific DOM operation that depends on it.

This concept is known as fine-grained reactivity.

---

How Does SolidJS Work?

To understand SolidJS, imagine a page displaying this:

Welcome, Ankit

Messages: 5

Suppose the number of messages changes from 5 to 6.

SolidJS does not need to treat the entire component as something that must be rendered again.

Instead, it knows which reactive value changed and which DOM expression depends on it.

Conceptually:

Reactive State
      ↓
Dependency Tracking
      ↓
Affected UI
      ↓
Direct DOM Update

Only the necessary part of the interface is updated.

This is one of the fundamental ideas behind SolidJS.

---

What Is Fine-Grained Reactivity?

Fine-grained reactivity means tracking dependencies at a very small level.

Consider:

const [count, setCount] = createSignal(0);

Here, count is reactive.

Now imagine:

<p>Count: {count()}</p>

SolidJS understands that this particular expression depends on count.

When you execute:

setCount(10);

SolidJS updates the relevant text in the DOM.

It does not need to recreate the entire component tree.

This dependency tracking is a major part of SolidJS’s performance model.

---

SolidJS Signals Explained

Signals are one of the most important concepts to learn in SolidJS.

A signal is a reactive value that can notify dependent computations when its value changes.

Signals can be created using createSignal().

Example:

import { createSignal } from "solid-js";

function Counter() {
  const [count, setCount] = createSignal(0);

  return (
    <div>
      <h2>{count()}</h2>

      <button onClick={() => setCount(count() + 1)}>
        Increase
      </button>
    </div>
  );
}

export default Counter;

Here:

count()

reads the current value.

And:

setCount()

updates the value.

For example:

setCount(5);

changes the counter to 5.

---

SolidJS vs React State

React developers may notice some similarities.

React:

const [count, setCount] = useState(0);

SolidJS:

const [count, setCount] = createSignal(0);

They look similar, but their behavior is different.

In React, updating state generally causes the component function to run again so React can determine what needs to change.

In SolidJS, components generally execute once during setup. Reactive expressions then update independently when their dependencies change.

This architectural difference is extremely important.

---

Does SolidJS Use a Virtual DOM?

No.

SolidJS does not use a Virtual DOM for normal DOM updates.

A Virtual DOM is an in-memory representation of the UI used by libraries such as React.

A simplified React-style process looks like:

State Changes
     ↓
Component Renders
     ↓
New Virtual DOM
     ↓
Compare Changes
     ↓
Update Real DOM

SolidJS follows a different model:

Signal Changes
     ↓
Reactive Dependency Runs
     ↓
Update Relevant DOM

By removing the need for Virtual DOM reconciliation, SolidJS can perform very efficient UI updates.

---

Key Features of SolidJS

SolidJS provides several features that make it attractive for modern frontend development.

1. Fine-Grained Reactivity

SolidJS tracks exactly which computations depend on reactive values.

When data changes, only the relevant computations need to run.

This can reduce unnecessary UI work.

---

2. No Virtual DOM

SolidJS updates the DOM through compiled reactive operations instead of maintaining and comparing Virtual DOM trees.

This is one of its biggest architectural differences from React.

---

3. JSX Support

SolidJS supports JSX.

For example:

function App() {
  return (
    <main>
      <h1>My Solid App</h1>
      <p>Learning SolidJS is fun.</p>
    </main>
  );
}

Developers familiar with React can therefore find the syntax approachable.

However, you should not assume React and SolidJS behave identically simply because both use JSX.

---

4. Reusable Components

SolidJS applications can be divided into reusable components.

Example:

function Button(props) {
  return (
    <button onClick={props.onClick}>
      {props.children}
    </button>
  );
}

You could then reuse the component throughout your application.

---

5. Reactive Primitives

SolidJS provides several primitives for managing reactive application logic.

Common examples include:

createSignal
createEffect
createMemo
createStore
createResource

Each solves a different problem.

---

createSignal()

createSignal() stores reactive state.

Example:

const [name, setName] = createSignal("Alex");

Read the value:

name()

Change the value:

setName("Sam");

Any reactive computation depending on name() can automatically respond to the change.

---

createEffect()

createEffect() allows you to run reactive side effects.

Example:

import { createEffect, createSignal } from "solid-js";

const [count, setCount] = createSignal(0);

createEffect(() => {
  console.log("Count:", count());
});

Whenever count() changes, the effect runs again.

This is useful for operations that should react to changing data.

---

createMemo()

createMemo() creates a derived reactive value.

Example:

const [price, setPrice] = createSignal(100);
const [quantity, setQuantity] = createSignal(2);

const total = createMemo(() => {
  return price() * quantity();
});

Now:

total()

returns the calculated total.

If price or quantity changes, the memo can update accordingly.

This is useful for calculations based on other reactive values.

---

createStore()

For more structured or nested state, SolidJS provides stores.

Example:

import { createStore } from "solid-js/store";

const [user, setUser] = createStore({
  name: "Alex",
  age: 25,
  location: "New York"
});

You can access properties normally:

console.log(user.name);

Stores can be especially helpful when working with objects and nested application state.

---

createResource()

Modern applications frequently retrieve data from APIs.

SolidJS provides createResource() to help manage asynchronous data.

Example:

import { createResource } from "solid-js";

const fetchUsers = async () => {
  const response = await fetch(
    "https://example.com/api/users"
  );

  return response.json();
};

const [users] = createResource(fetchUsers);

Resources are useful when working with server data and asynchronous operations.

---

How to Install SolidJS

One of the easiest ways to start a SolidJS project is through its official project scaffolding.

A common command is:

npm init solid@latest

Follow the prompts to configure the project.

After creating the project, move into its directory:

cd my-solid-app

Install the dependencies if necessary:

npm install

Then start the development server:

npm run dev

Your terminal will display the local development URL.

Open it in your browser to see the application.

---

Basic SolidJS Project Structure

A SolidJS project may contain files and directories similar to:

my-solid-app/
│
├── src/
│   ├── App.jsx
│   ├── index.jsx
│   └── assets/
│
├── public/
├── package.json
└── vite.config.js

The exact structure depends on the template and tooling you choose.

The src directory generally contains most of your application code.

---

Your First SolidJS Application

Here is a simple counter application:

import { createSignal } from "solid-js";

function App() {
  const [count, setCount] = createSignal(0);

  return (
    <main>
      <h1>SolidJS Counter</h1>

      <p>Current Count: {count()}</p>

      <button onClick={() => setCount(count() + 1)}>
        Increase
      </button>

      <button onClick={() => setCount(count() - 1)}>
        Decrease
      </button>
    </main>
  );
}

export default App;

This example demonstrates several SolidJS fundamentals:

• components
• JSX
• signals
• event handling
• reactive UI updates

---

Conditional Rendering in SolidJS

SolidJS provides control-flow components such as <Show>.

Example:

import { createSignal, Show } from "solid-js";

function App() {
  const [loggedIn, setLoggedIn] = createSignal(false);

  return (
    <Show
      when={loggedIn()}
      fallback={<p>Please log in.</p>}
    >
      <p>Welcome back!</p>
    </Show>
  );
}

The content displayed depends on the value of loggedIn().

---

Rendering Lists in SolidJS

SolidJS provides <For> for efficiently rendering collections.

Example:

import { For } from "solid-js";

function App() {
  const users = [
    { id: 1, name: "Alex" },
    { id: 2, name: "John" },
    { id: 3, name: "Sara" }
  ];

  return (
    <ul>
      <For each={users}>
        {(user) => <li>{user.name}</li>}
      </For>
    </ul>
  );
}

This is commonly used for:

• product lists
• user lists
• messages
• comments
• notifications
• search results

---

Event Handling in SolidJS

Event handling is straightforward.

Example:

function App() {
  const handleClick = () => {
    console.log("Button clicked");
  };

  return (
    <button onClick={handleClick}>
      Click Me
    </button>
  );
}

You can handle common browser events such as:

onClick
onInput
onChange
onSubmit
onKeyDown
onMouseEnter

---

Form Handling in SolidJS

Signals work well with form inputs.

Example:

import { createSignal } from "solid-js";

function App() {
  const [name, setName] = createSignal("");

  return (
    <div>
      <input
        type="text"
        value={name()}
        onInput={(event) => setName(event.currentTarget.value)}
      />

      <p>Hello, {name()}</p>
    </div>
  );
}

As the user types, the signal changes and the displayed value updates.

---

SolidJS Props

Props allow data to be passed from one component to another.

Example:

function UserCard(props) {
  return (
    <div>
      <h2>{props.name}</h2>
      <p>{props.role}</p>
    </div>
  );
}

Use it like:

<UserCard
  name="Alex"
  role="Frontend Developer"
/>

Props are a fundamental part of building reusable component-based interfaces.

---

SolidJS vs React

SolidJS and React may look similar because both commonly use JSX, but their rendering models are different.

Feature	SolidJS	React
JSX	Yes	Yes
Component Based	Yes	Yes
Virtual DOM	No	Yes
Fine-Grained Reactivity	Yes	Not its primary rendering model
State Primitive	Signals	Hooks/state APIs
Component Re-execution	Generally not for reactive updates	Common
Ecosystem Size	Smaller	Very large
Learning Resources	Growing	Extensive

React has a much larger ecosystem and job market.

SolidJS, however, offers an interesting reactive architecture and can deliver excellent runtime performance.

---

SolidJS vs Svelte

SolidJS and Svelte both focus heavily on efficient frontend rendering, but they use different programming models.

Svelte relies heavily on compilation and its own component syntax.

SolidJS uses JSX and fine-grained reactive primitives.

A React developer may find SolidJS syntax more immediately familiar because of JSX.

Svelte developers may recognize some of the broader ideas around avoiding unnecessary runtime rendering work.

Neither is universally better. The right choice depends on your project, team, ecosystem requirements, and preferred development model.

---

Advantages of SolidJS

SolidJS offers several important advantages.

Excellent Performance

Fine-grained reactivity allows SolidJS to update only the UI operations affected by changing data.

Familiar JSX

Developers coming from React can understand much of the basic syntax quickly.

No Virtual DOM

SolidJS avoids Virtual DOM diffing for standard reactive DOM updates.

Reactive by Design

Signals and reactive primitives provide a direct model for connecting state to computations and UI.

Small and Efficient

SolidJS is designed to keep runtime overhead relatively low while delivering responsive interfaces.

Component-Based Development

Applications can be organized into small, reusable components.

---

Limitations of SolidJS

SolidJS also has disadvantages that beginners should understand.

Smaller Ecosystem

React has existed for much longer and has a massive ecosystem.

SolidJS has fewer third-party libraries and integrations.

Smaller Job Market

Companies hiring specifically for SolidJS are less common than companies hiring React, Angular, or Vue developers.

Smaller Community

The community is active but significantly smaller than the largest frontend ecosystems.

React Similarities Can Be Misleading

React developers may initially assume SolidJS works like React because both use JSX.

However, patterns that make sense in React may not always be appropriate in SolidJS because their reactive models differ.

---

What Can You Build with SolidJS?

SolidJS can be used to build many types of web applications.

Examples include:

• SaaS dashboards
• admin panels
• e-commerce interfaces
• productivity tools
• real-time applications
• analytics dashboards
• portfolio websites
• interactive websites
• social platforms
• internal business tools
• API-powered web apps

SolidJS can be particularly attractive when you want a reactive interface with efficient updates.

---

What Is SolidStart?

When learning SolidJS, you may also encounter SolidStart.

SolidStart is the application framework for building full applications with Solid.

While SolidJS focuses primarily on UI and reactivity, SolidStart provides application-level capabilities such as routing, server functionality, data loading, and rendering strategies.

A simplified way to think about the relationship is:

SolidJS → UI and reactivity

SolidStart → Full application framework built around Solid

This is somewhat similar conceptually to how frontend ecosystems often have a core UI library and a larger framework built around it.

---

Is SolidJS Good for Beginners?

Yes, but there is an important consideration.

If you already understand:

• HTML
• CSS
• JavaScript
• ES6+
• DOM basics
• components
• basic frontend development

SolidJS should be relatively approachable.

If you are completely new to web development, learn JavaScript fundamentals first.

A recommended learning order is:

HTML
↓
CSS
↓
JavaScript
↓
Modern JavaScript / ES6+
↓
DOM and Browser Basics
↓
SolidJS
↓
APIs
↓
Routing
↓
State Management
↓
SolidStart

Strong JavaScript fundamentals will make learning any modern frontend technology much easier.

---

Should You Learn React Before SolidJS?

No.

React is not a requirement for learning SolidJS.

However, knowing React can make JSX and component concepts feel familiar.

If your main goal is employment, React may currently offer more opportunities because of its much larger adoption.

If your goal is to explore modern reactive architecture, build highly interactive applications, or broaden your frontend knowledge, SolidJS is worth learning.

---

Is SolidJS Faster Than React?

SolidJS is designed around fine-grained reactive updates and avoids Virtual DOM reconciliation.

As a result, it can perform extremely well in many UI benchmarks and workloads.

However, saying one framework is always “faster” can be misleading.

Real application performance depends on many factors, including:

• application architecture
• network requests
• bundle size
• JavaScript execution
• rendering complexity
• images and assets
• third-party scripts
• developer implementation
• server performance

Framework benchmarks are useful, but they should not be the only reason for choosing a technology.

---

SolidJS Learning Roadmap

If you want to become comfortable with SolidJS, follow this progression:

Step 1: Learn JavaScript

Understand variables, functions, objects, arrays, modules, promises, async/await, and modern JavaScript syntax.

Step 2: Learn JSX

Understand how JavaScript expressions and HTML-like syntax work together.

Step 3: Learn Components

Build small reusable UI components.

Step 4: Learn Signals

Practice:

createSignal()

Signals are central to SolidJS development.

Step 5: Learn Reactive Primitives

Study:

createEffect()
createMemo()
createStore()
createResource()

Step 6: Learn Control Flow

Understand components such as:

<Show>
<For>
<Switch>
<Match>

Step 7: Work with APIs

Learn how to retrieve and display data from REST APIs.

Step 8: Learn Routing

Build applications with multiple pages and routes.

Step 9: Explore SolidStart

Move from basic frontend applications toward complete Solid-based web applications.

Step 10: Build Real Projects

Practical development is the fastest way to strengthen your knowledge.

---

SolidJS Project Ideas for Beginners

Once you understand the basics, try building projects such as:

1. Counter application
2. Todo application
3. Weather application
4. Notes application
5. Expense tracker
6. Movie search application
7. Product catalog
8. Blog frontend
9. Admin dashboard
10. Real-time chat interface

Start with small applications and gradually introduce APIs, authentication, databases, and server functionality.

---

Who Should Learn SolidJS?

SolidJS can be useful for:

• frontend developers
• JavaScript developers
• React developers
• full-stack developers
• developers interested in reactive programming
• developers exploring alternatives to React
• developers building performance-focused interfaces

It is also a useful technology for understanding how fine-grained reactive systems differ from component re-rendering architectures.

---

Is SolidJS Worth Learning?

SolidJS is worth learning if you want to expand your understanding of modern frontend development.

Its combination of JSX, signals, fine-grained reactivity, reusable components, and direct DOM updates provides a different approach from Virtual DOM-based libraries.

However, technology selection should always depend on your goals.

For maximum job opportunities, larger ecosystems such as React remain important.

For learning modern reactive concepts and experimenting with highly efficient UI updates, SolidJS is an excellent technology to explore.

---

Frequently Asked Questions

What is SolidJS used for?

SolidJS is used to build interactive and reactive web user interfaces, including dashboards, SaaS products, e-commerce interfaces, productivity applications, and other modern web applications.

Is SolidJS a framework or library?

SolidJS is commonly described as a declarative JavaScript library for building user interfaces. SolidStart provides a broader application framework around Solid.

Does SolidJS use React?

No.

SolidJS is an independent project and does not depend on React.

Does SolidJS use JSX?

Yes.

SolidJS supports JSX for creating user interfaces.

Does SolidJS use a Virtual DOM?

No.

SolidJS uses fine-grained reactivity and compiled DOM operations instead of a traditional Virtual DOM reconciliation system.

Is SolidJS difficult to learn?

SolidJS is relatively approachable if you already understand JavaScript, JSX, and component-based frontend development.

Can I build large applications with SolidJS?

Yes.

SolidJS can be used for both small and larger applications. However, you should evaluate ecosystem support, available libraries, team experience, and long-term project requirements before choosing any frontend technology.

Is SolidJS better than React?

Neither is universally better.

React offers a much larger ecosystem, community, and job market. SolidJS offers a different reactive architecture with efficient fine-grained updates.

Do I need React before learning SolidJS?

No.

You can learn SolidJS directly after developing a solid understanding of JavaScript and web fundamentals.

What should I learn after SolidJS?

After learning SolidJS fundamentals, continue with routing, API integration, authentication, testing, TypeScript, deployment, and SolidStart.

---

Conclusion

SolidJS is a modern JavaScript UI library built around fine-grained reactivity and efficient DOM updates.

Although its JSX syntax can look similar to React, its internal model is fundamentally different. Rather than relying on a Virtual DOM and repeatedly rendering components when state changes, SolidJS tracks reactive dependencies and updates the specific parts of the interface that need to change.

The most important concepts for beginners are:

• components
• JSX
• signals
• fine-grained reactivity
• createEffect
• createMemo
• stores
• resources
• control flow
• SolidStart

If you already know JavaScript and want to explore a modern approach to reactive frontend development, SolidJS is a valuable technology to add to your learning roadmap.

Start with a simple counter or todo application, understand signals thoroughly, and then gradually move toward API-powered applications and SolidStart.