Learn Lit - 9 Code Examples & CST Typing Practice Test

Lit is a lightweight, fast, web-component-focused library for building reactive and declarative UI using standard web platform features. It emphasizes interoperability, small bundle sizes, and declarative templating with lit-html.

View all 9 Lit code examples →

Lit Counter Component Lit Counter with Step Increment Lit Counter with Max Limit Lit Counter with Auto-Reset Lit Counter with History Lit Counter with Dark Mode Only Lit Counter with Auto-Increment Lit Counter with Conditional Theme Lit Full Featured Counter

Learn LIT with Real Code Examples

Updated Nov 22, 2025

Explain

Lit allows developers to create reusable components using standard web components.

It provides reactive properties and declarative templates to make UI updates efficient.

Lit focuses on minimal JavaScript overhead while supporting rich interactivity.

Core Features

Custom Elements integration

Shadow DOM encapsulation

Reactive property system

Declarative rendering

Event binding & lifecycle hooks

Basic Concepts Overview

LitElement base class

Reactive properties and state

Shadow DOM encapsulation

HTML templating with lit-html

CSS styles scoped to component

Project Structure

src/components - Lit components

src/styles - shared styles

index.html - main entry

package.json - dependencies

tsconfig.json - optional TypeScript support

Building Workflow

Define a LitElement subclass

Add reactive properties

Create render() template with `html`

Attach scoped styles

Use component in HTML or other frameworks

Difficulty Use Cases

Beginner: simple button component

Intermediate: interactive form components

Advanced: reusable widget libraries

Expert: large design systems

Community: open-source web components

Comparisons

More lightweight than React or Vue

Standards-compliant vs framework-specific

Better for reusable components than Angular

Faster runtime updates

Smaller ecosystem than major frameworks

Versioning Timeline

2019 - Lit 2.0 initial release

2020 - Improved reactive system & TypeScript support

2021 - Scoped styling & Shadow DOM improvements

2022 - Expanded tooling & Open-WC integration

2025 - Modernized reactive updates and ecosystem growth

Glossary

LitElement: Base class for components

Reactive properties: Data-bound properties that trigger updates

Shadow DOM: Encapsulated DOM for components

lit-html: Tagged template literal for declarative rendering

Custom elements: Standard web components

Code Sample Descriptions

Lit Counter Component

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-counter')
export class LitCounter extends LitElement {
    @state() count = 0;
    @state() isDark = false;

    static styles = css`
        .dark-theme { background-color: #222; color: #eee; }
        .light-theme { background-color: #fff; color: #000; }
    `;

    render() {
        return html`
        <div class=${this.isDark ? 'dark-theme' : 'light-theme'}>
        <h2>Counter: ${this.count}</h2>
        <div>
        <button @click=${() => this.count++}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>
        <button @click=${() => this.isDark = !this.isDark}>Switch to ${this.isDark ? 'Light' : 'Dark'} Theme</button>
        </div>
        `;
    }
}

A basic LitElement counter component with dark/light theme toggle.

Let’s Try →

Lit Counter with Step Increment

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-step-counter')
export class LitStepCounter extends LitElement {
    @state() count = 0;
    step = 2;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count += this.step}>+</button>
        <button @click=${() => this.count -= this.step}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Counter increments/decrements by a specified step value.

Let’s Try →

Lit Counter with Max Limit

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-max-counter')
export class LitMaxCounter extends LitElement {
    @state() count = 0;
    max = 5;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count < this.max ? this.count++ : null}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Stops incrementing after a maximum count is reached.

Let’s Try →

Lit Counter with Auto-Reset

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-auto-reset-counter')
export class LitAutoResetCounter extends LitElement {
    @state() count = 0;
    threshold = 10;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => { this.count = (this.count + 1 > this.threshold) ? 0 : this.count + 1; }}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Automatically resets when counter exceeds threshold.

Let’s Try →

Lit Counter with History

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-history-counter')
export class LitHistoryCounter extends LitElement {
    @state() count = 0;
    @state() history = [];
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <div>History: ${this.history.join(', ')}</div>
        <button @click=${() => { this.count++; this.history = [...this.history, 'Increment']; }}>+</button>
        <button @click=${() => { this.count--; this.history = [...this.history, 'Decrement']; }}>-</button>
        <button @click=${() => { this.count = 0; this.history = [...this.history, 'Reset']; }}>Reset</button>
        </div>`;
    }
}

Tracks increment/decrement history.

Let’s Try →

Lit Counter with Dark Mode Only

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-dark-counter')
export class LitDarkCounter extends LitElement {
    @state() isDark = false;
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() {
        return html`<div class=${this.isDark?'dark-theme':'light-theme'}>
        <h2>Counter: 0</h2>
        <button @click=${() => this.isDark = !this.isDark}>Toggle Theme</button>
        </div>`;
    }
}

Static counter with only dark/light theme toggle.

Let’s Try →

Lit Counter with Auto-Increment

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-auto-increment-counter')
export class LitAutoIncrementCounter extends LitElement {
    @state() count = 0;
    connectedCallback() { super.connectedCallback(); this.interval = setInterval(() => this.count++, 1000); }
    disconnectedCallback() { clearInterval(this.interval); super.disconnectedCallback(); }
    render() { return html`<div><h2>Counter: ${this.count}</h2></div>`; }
}

Automatically increments counter every second.

Let’s Try →

Lit Counter with Conditional Theme

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-conditional-theme-counter')
export class LitConditionalThemeCounter extends LitElement {
    @state() count = 0;
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() {
        const isDark = this.count % 2 === 0;
        return html`<div class=${isDark?'dark-theme':'light-theme'}>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count++}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count=0}>Reset</button>
        </div>`;
    }
}

Theme changes automatically based on even/odd counter value.

Let’s Try →

Lit Full Featured Counter

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-full-counter')
export class LitFullCounter extends LitElement {
    @state() count = 0;
    @state() history = [];
    @state() isDark = false;
    step = 2;
    max = 10;
    connectedCallback() { super.connectedCallback(); this.interval = setInterval(()=>{ let c=this.count+this.step; if(c>this.max)c=0; this.count=c; this.history=[...this.history,'Auto Increment']; },1000); }
    disconnectedCallback() { clearInterval(this.interval); super.disconnectedCallback(); }
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() { return html`<div class=${this.isDark?'dark-theme':'light-theme'}>
    <h2>Counter: ${this.count}</h2>
    <div>History: ${this.history.join(', ')}</div>
    <button @click=${()=>{ this.count+=this.step; this.history=[...this.history,'Increment']; }}>+</button>
    <button @click=${()=>{ this.count-=this.step; this.history=[...this.history,'Decrement']; }}>-</button>
    <button @click=${()=>{ this.count=0; this.history=[...this.history,'Reset']; }}>Reset</button>
    <button @click=${()=>this.isDark=!this.isDark}>Toggle Theme</button>
</div>`; }
}

Combines step increment, max limit, auto-reset, history, auto-increment, and theme toggle.

Let’s Try →

Frequently Asked Questions about Lit

What is Lit?

What are the primary use cases for Lit?

Reusable web components. Design systems. Embeddable widgets for websites. Progressive enhancement projects. Small, high-performance UI components

What are the strengths of Lit?

Minimal bundle size. Interoperable with any framework. Standards-based approach. Great for web component libraries. Fast rendering & updates

What are the limitations of Lit?

Not a full-stack framework. Requires knowledge of web components. Limited routing or state management built-in. Smaller ecosystem than React/Vue. Less beginner-friendly than higher-level frameworks

How can I practice Lit typing speed?

CodeSpeedTest offers 9+ real Lit code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

Learn Other Programming Languages

C React Python C++Rust TypeScript Kotlin PHP Java C#Ruby Mql Cql N1ql Cypher Gremlin Partiql Haskell Elixir Fsharp View all languages →

Code Sample Descriptions

Lit Counter Component

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-counter')
export class LitCounter extends LitElement {
    @state() count = 0;
    @state() isDark = false;

    static styles = css`
        .dark-theme { background-color: #222; color: #eee; }
        .light-theme { background-color: #fff; color: #000; }
    `;

    render() {
        return html`
        <div class=${this.isDark ? 'dark-theme' : 'light-theme'}>
        <h2>Counter: ${this.count}</h2>
        <div>
        <button @click=${() => this.count++}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>
        <button @click=${() => this.isDark = !this.isDark}>Switch to ${this.isDark ? 'Light' : 'Dark'} Theme</button>
        </div>
        `;
    }
}

A basic LitElement counter component with dark/light theme toggle.

Let’s Try →

Lit Counter with Step Increment

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-step-counter')
export class LitStepCounter extends LitElement {
    @state() count = 0;
    step = 2;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count += this.step}>+</button>
        <button @click=${() => this.count -= this.step}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Counter increments/decrements by a specified step value.

Let’s Try →

Lit Counter with Max Limit

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-max-counter')
export class LitMaxCounter extends LitElement {
    @state() count = 0;
    max = 5;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count < this.max ? this.count++ : null}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Stops incrementing after a maximum count is reached.

Let’s Try →

Lit Counter with Auto-Reset

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-auto-reset-counter')
export class LitAutoResetCounter extends LitElement {
    @state() count = 0;
    threshold = 10;
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => { this.count = (this.count + 1 > this.threshold) ? 0 : this.count + 1; }}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count = 0}>Reset</button>
        </div>`;
    }
}

Automatically resets when counter exceeds threshold.

Let’s Try →

Lit Counter with History

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-history-counter')
export class LitHistoryCounter extends LitElement {
    @state() count = 0;
    @state() history = [];
    render() {
        return html`<div>
        <h2>Counter: ${this.count}</h2>
        <div>History: ${this.history.join(', ')}</div>
        <button @click=${() => { this.count++; this.history = [...this.history, 'Increment']; }}>+</button>
        <button @click=${() => { this.count--; this.history = [...this.history, 'Decrement']; }}>-</button>
        <button @click=${() => { this.count = 0; this.history = [...this.history, 'Reset']; }}>Reset</button>
        </div>`;
    }
}

Tracks increment/decrement history.

Let’s Try →

Lit Counter with Dark Mode Only

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-dark-counter')
export class LitDarkCounter extends LitElement {
    @state() isDark = false;
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() {
        return html`<div class=${this.isDark?'dark-theme':'light-theme'}>
        <h2>Counter: 0</h2>
        <button @click=${() => this.isDark = !this.isDark}>Toggle Theme</button>
        </div>`;
    }
}

Static counter with only dark/light theme toggle.

Let’s Try →

Lit Counter with Auto-Increment

import { LitElement, html } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-auto-increment-counter')
export class LitAutoIncrementCounter extends LitElement {
    @state() count = 0;
    connectedCallback() { super.connectedCallback(); this.interval = setInterval(() => this.count++, 1000); }
    disconnectedCallback() { clearInterval(this.interval); super.disconnectedCallback(); }
    render() { return html`<div><h2>Counter: ${this.count}</h2></div>`; }
}

Automatically increments counter every second.

Let’s Try →

Lit Counter with Conditional Theme

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-conditional-theme-counter')
export class LitConditionalThemeCounter extends LitElement {
    @state() count = 0;
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() {
        const isDark = this.count % 2 === 0;
        return html`<div class=${isDark?'dark-theme':'light-theme'}>
        <h2>Counter: ${this.count}</h2>
        <button @click=${() => this.count++}>+</button>
        <button @click=${() => this.count--}>-</button>
        <button @click=${() => this.count=0}>Reset</button>
        </div>`;
    }
}

Theme changes automatically based on even/odd counter value.

Let’s Try →

Lit Full Featured Counter

import { LitElement, html, css } from 'lit';
import { customElement, state } from 'lit/decorators.js';

@customElement('lit-full-counter')
export class LitFullCounter extends LitElement {
    @state() count = 0;
    @state() history = [];
    @state() isDark = false;
    step = 2;
    max = 10;
    connectedCallback() { super.connectedCallback(); this.interval = setInterval(()=>{ let c=this.count+this.step; if(c>this.max)c=0; this.count=c; this.history=[...this.history,'Auto Increment']; },1000); }
    disconnectedCallback() { clearInterval(this.interval); super.disconnectedCallback(); }
    static styles = css`.dark-theme{background:#222;color:#eee}.light-theme{background:#fff;color:#000}`;
    render() { return html`<div class=${this.isDark?'dark-theme':'light-theme'}>
    <h2>Counter: ${this.count}</h2>
    <div>History: ${this.history.join(', ')}</div>
    <button @click=${()=>{ this.count+=this.step; this.history=[...this.history,'Increment']; }}>+</button>
    <button @click=${()=>{ this.count-=this.step; this.history=[...this.history,'Decrement']; }}>-</button>
    <button @click=${()=>{ this.count=0; this.history=[...this.history,'Reset']; }}>Reset</button>
    <button @click=${()=>this.isDark=!this.isDark}>Toggle Theme</button>
</div>`; }
}

Combines step increment, max limit, auto-reset, history, auto-increment, and theme toggle.

Let’s Try →

Frequently Asked Questions about Lit

What is Lit?

What are the primary use cases for Lit?

Reusable web components. Design systems. Embeddable widgets for websites. Progressive enhancement projects. Small, high-performance UI components

What are the strengths of Lit?

Minimal bundle size. Interoperable with any framework. Standards-based approach. Great for web component libraries. Fast rendering & updates

What are the limitations of Lit?

Not a full-stack framework. Requires knowledge of web components. Limited routing or state management built-in. Smaller ecosystem than React/Vue. Less beginner-friendly than higher-level frameworks

How can I practice Lit typing speed?

CodeSpeedTest offers 9+ real Lit code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

Learn Lit - 9 Code Examples & CST Typing Practice Test

Learn LIT with Real Code Examples

Explain

Core Features

Basic Concepts Overview

Project Structure

Building Workflow

Difficulty Use Cases

Comparisons

Versioning Timeline

Glossary

Installation Setup

Environment Setup

Config Files

Cli Commands

Internationalization

Accessibility

Ui Styling

State Management

Data Management

Architecture

Rendering Model

Architectural Patterns

Real World Architectures

Design Principles

Scalability Guide

Migration Guide

Performance Notes

Security Notes

Monitoring Analytics

Code Quality

Practical Examples

Troubleshooting

Testing Guide

Deployment Options

Tools Ecosystem

Integrations

Productivity Tips

Challenges

Learning Path

Skill Improvement Plan

Interview Questions

Cheat Sheet

Books

Tutorials

Official Docs

Community Links

Community Support

Monetization

Future Roadmap

When Not To Use

Final Summary

Faq

Code Sample Descriptions

Lit Counter Component

Lit Counter with Step Increment

Lit Counter with Max Limit

Lit Counter with Auto-Reset

Lit Counter with History

Lit Counter with Dark Mode Only

Lit Counter with Auto-Increment

Lit Counter with Conditional Theme

Lit Full Featured Counter

Frequently Asked Questions about Lit

What is Lit?

What are the primary use cases for Lit?

What are the strengths of Lit?

What are the limitations of Lit?

How can I practice Lit typing speed?

Learn Other Programming Languages

Learn Lit - 9 Code Examples & CST Typing Practice Test

Learn LIT with Real Code Examples

Explain

Core Features

Basic Concepts Overview

Project Structure

Building Workflow

Difficulty Use Cases

Comparisons

Versioning Timeline