Best Online JavaScript Compilers 2026 (Comparison)

Looking for the best online JavaScript compiler? We've tested the most popular options and compared them on speed, features, and developer experience. Here's our verdict for 2026.

What We Looked For

We evaluated each online JavaScript compiler on these criteria:

• Compilation speed: How fast does code compile and preview?
• Language support: TypeScript, JSX, ES2026, etc.
• npm packages: Can you import npm modules?
• Editor quality: Syntax highlighting, autocomplete, error detection
• Features: Multi-file projects, saving, sharing, publishing
• AI assistance: Does it have AI coding help?
• Price: Free tier and paid options

1. PlayCode: Best Overall

PlayCode is our top pick for 2026. It combines the fastest compilation we've tested with a professional editor and unique features no competitor offers.

Pros:

• Fastest compilation (20-50ms incremental builds)
• Full npm package support (React, Three.js, Lodash, etc.)
• AI coding assistant that can write, edit, and debug code
• Real-time collaboration (multiple users editing simultaneously)
• Auto-save to cloud (never lose your work)
• File uploads (images, assets, any file type)
• Flexible layout (resize, move, arrange panels your way)
• Beautiful, modern design (best UI in the market)
• Real-time error highlighting (bug finder)
• 100+ templates (React apps, landing pages, games, etc.)
• TypeScript, JSX, ES2026, React, Vue, Svelte, Angular
• Works offline after initial load
• Mobile-first (works perfectly on phones and tablets)
• One-click publish (your app is live instantly)
• Custom domains (attach your own domain, full website hosting)

Cons:

• AI features require Pro subscription
• No server-side code (Node.js backend)

Best for: Developers who want the fastest, most feature-rich experience with collaboration and AI assistance.

Price: Free with unlimited coding. Pro ($9.99/month) for AI and advanced features.

2. Programiz: Best for Beginners

Programiz focuses on learning. Their JavaScript compiler is simple and comes with tutorials and examples built in.

Pros:

• Clean, simple interface
• Integrated tutorials and examples
• No signup required
• Good for learning basics

Cons:

• No npm package support
• No TypeScript or JSX
• Single file only
• Limited editor features
• No AI assistance

Best for: Absolute beginners learning JavaScript fundamentals.

Price: Free

3. OneCompiler: Good Free Option

OneCompiler offers a straightforward JavaScript compiler with support for many other languages too.

Pros:

• Supports 60+ programming languages
• Code sharing and embedding
• No signup required
• Decent compilation speed

Cons:

• Basic editor (no IntelliSense)
• Limited npm support
• No TypeScript or JSX
• No AI features
• Ads on free tier

Best for: Quick code snippets across multiple languages.

Price: Free with ads. Premium removes ads.

4. CodePen: Best for CSS/HTML Demos

CodePen is the classic choice for front-end demos. It excels at HTML/CSS work but has limited JavaScript compilation features.

Pros:

• Huge community and example library
• Great for CSS demos and animations
• Embedding support for blogs
• Collaborative editing

Cons:

• Slow JavaScript compilation
• No TypeScript support (without preprocessor config)
• Limited npm packages (CDN only)
• No AI assistance
• No offline support

Best for: CSS demos and sharing front-end examples.

Price: Free tier. Pro ($12/month) for private pens and features.

5. JSFiddle: Classic, but Aging

JSFiddle pioneered online JavaScript editing but hasn't kept up with modern tools.

Pros:

• Simple, familiar interface
• Good for quick tests
• Collaboration features

Cons:

• Dated interface
• Slower compilation
• No npm packages
• No TypeScript
• No AI features

Best for: Developers who prefer the familiar JSFiddle workflow.

Price: Free

Feature Comparison Table

What Sets PlayCode Apart in 2026

PlayCode isn't just another online compiler. It's a complete development environment with features no competitor offers:

AI Coding Assistant:

• Write code from natural language descriptions
• Debug and fix errors automatically
• Explain how code works
• Refactor and optimize your code
• Work across multiple files in your project

Real-time Collaboration:

• Multiple developers can edit the same project simultaneously
• See each other's cursors and changes in real-time
• Perfect for pair programming and teaching

Professional IDE Features:

• Flexible, customizable layout (resize and move any panel)
• 100+ templates to start from (React apps, games, landing pages)
• File uploads for images and assets
• Beautiful, modern design
• Mobile-first (works great on phones and tablets)

Built-in Hosting (No Competitor Has This):

• One-click publish: your app is live instantly on a PlayCode URL
• Custom domains: attach your own domain for a full production website
• No deployment setup, no hosting provider, no DNS configuration
• Go from code to live website in seconds

This transforms PlayCode from a simple code runner into a complete development platform.

Our Verdict

For most developers in 2026, PlayCode is the best online JavaScript compiler. It's the fastest, most feature-complete, and the only one with AI assistance.

If you're an absolute beginner learning JavaScript basics, Programiz's simpler interface might be less overwhelming. And if you're doing CSS demos, CodePen's community is unmatched.

But for serious JavaScript development, including TypeScript, React, Vue, npm packages, and AI help, PlayCode is the clear winner.

Try PlayCode Free

Ready to try the best JavaScript compiler? Start coding for free and see the difference instant compilation and AI assistance make.