Kelvin Kiptum Kiprop

Posted on Jan 25

Building a Modern Browser-Based Code Editor

#showdev #typescript #react #webdev

Code Editor X: Building a Modern Browser-Based Code Editor

A deep dive into creating a VS Code-inspired development environment using cutting-edge web technologies

TL;DR

Code Editor X is a VS Code-inspired, browser-based code editor built with React 19, TypeScript, CodeMirror 6, Tailwind CSS 4, and Radix UI.

What it does: Multi-file editing with tabs and file tree, syntax highlighting for multiple languages, AI chat assistant, project dashboard, persistent local storage, and full customization.

Why it matters: Zero installation, lightweight, works on any device, built on modern tech, accessible by design.

Introduction

The browser has become a legitimate platform for serious software development. Code Editor X is a modern, browser-based code editor built from the ground up with React 19, TypeScript, and CodeMirror 6.

Why I Built This

I wanted to code from anywhere; my laptop, a borrowed computer, even a tablet, without installing anything. Traditional IDEs are powerful but heavy. They assume you have a dedicated machine with gigabytes to spare.

I also wanted to learn. React 19 had just landed with its concurrent rendering improvements. CodeMirror 6 promised blazing-fast editing. Tailwind CSS 4 was out. Building a code editor felt like the perfect way to push these technologies to their limits and understand them deeply.

Code Editor X started as an answer to a simple question: What if VS Code lived entirely in your browser?

Who Is This For?

Audience	Why It Works
Students	No setup—open browser, start coding
Prototypers	Lightweight environment for quick ideas
Teachers	Same environment for everyone, no "works on my machine"
Remote workers	Access projects from any device

Quick Comparison

Aspect	Traditional IDE	Code Editor X
Setup Time	Minutes to hours	Instant
Disk Space	Hundreds of MB	Zero
Cross-Platform	Different installers	Works everywhere
Resource Usage	500MB+ RAM	Lightweight

The Tech Stack

Every choice was deliberate.

React 19 + TypeScript

Concurrent rendering handles complex UI updates smoothly—multiple resizable panels, real-time syntax highlighting, instant theme switching. TypeScript catches bugs at compile time and serves as living documentation.

CodeMirror 6

The editor's heart. CM6 was rewritten from scratch for performance:

Compartments for dynamic reconfiguration without recreating the editor
Extensible architecture—every feature is a module
Mobile-friendly unlike many competitors

// Switch themes without recreating the editor
const themeCompartment = new Compartment();
view.dispatch({
  effects: themeCompartment.reconfigure(newTheme)
});

Radix UI + Tailwind CSS 4

Radix provides accessible component primitives (dialogs, dropdowns, tooltips) that work with screen readers and keyboard navigation. Tailwind makes styling fast and consistent.

IndexedDB + React Context

Offline-first persistence with IndexedDB: your work stays local, you own your data. React Context manages theme, settings, and project state without external dependencies.

What We've Built

The Layout

All panels are resizable, collapsible, and remember their state across sessions.

Core Features

File Tree: Hierarchical navigation with language-specific icons, create/rename/delete operations
Multi-Tab Editing: Dirty state indicators, tab management, auto-focus behavior
CodeMirror Editor: Syntax highlighting, line numbers, bracket matching, code folding, custom themes
AI Chat Panel: Context-aware help, code block support with copy functionality
Settings: Theme, font, tab size, word wrap, auto-save—all customizable
Dashboard: Project management with search, filters, and quick actions

Architecture

src/
├── components/
│   ├── layout/           # Shell layout
│   ├── editor-page/      # Editor components
│   └── ui/               # Reusable primitives
├── lib/
│   ├── theme-provider.tsx
│   ├── settings-provider.tsx
│   └── project-provider.tsx
└── types/

Three focused context providers handle state: ThemeProvider, SettingsProvider, ProjectProvider. Changes flow unidirectionally through IndexedDB.

What's Next?

Near-term: Terminal integration, git operations, more language support, find and replace

Medium-term: Real AI integration, collaborative editing, extensions system, cloud sync

Long-term: Debugger, build tools, deployment pipelines, mobile optimization

Conclusion

Code Editor X shows what's possible when modern web technologies combine thoughtfully. The browser is no longer a limitation, it's a feature.

Try It Out

Live Demo →

Or run locally:

git clone https://github.com/design-sparx/code-editor-x.git
cd code-editor-x
npm install
npm run dev

Open http://localhost:5173 and start coding.

Built with React 19, TypeScript, CodeMirror 6, Tailwind CSS 4, and Radix UI.

GitHub · Live Demo

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