Next.js Online Compiler | Free Online Compiler

Page (JSX)

const metadata = {
    title: "Next.js Starter",
    description: "App Router style layout and page."
};

function RootLayout({ children }) {
    return (
        <div className="shell">
            <header className="topbar">
                <div className="logo">Next</div>
                <nav className="nav">
                    <a href="#">Docs</a>
                    <a href="#">Solutions</a>
                    <a href="#">Blog</a>
                </nav>
            </header>
            <main className="content">{children}</main>
            <footer className="footer">Powered by React 18 patterns</footer>
        </div>
    );
}

function Page() {
    const features = [
        "File based routing",
        "Server components",
        "Streaming UI",
        "Edge ready"
    ];

return (
        <section className="hero">
            <p className="kicker">{metadata.description}</p>
            <h1>{metadata.title}</h1>
            <p className="lead">
                This browser sandbox mimics Next.js layout patterns.
            </p>
            <div className="grid">
                {features.map((item) => (
                    <div className="tile" key={item}>
                        <h3>{item}</h3>
                        <p>Swap this content or build your own page.</p>
                    </div>
                ))}
            </div>
            <button className="cta">Deploy</button>
        </section>
    );
}

const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(
    <RootLayout>
        <Page />
    </RootLayout>
);

CSS

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f5f5f5;
    color: #111;
}
.shell {
    min-height: 100vh;
    background: #ffffff;
}
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 30px;
    border-bottom: 1px solid #eee;
}
.logo {
    background: #111;
    color: #fff;
    padding: 6px 10px;
    border-radius: 4px;
    font-weight: bold;
    letter-spacing: 1px;
}
.nav a {
    margin-left: 16px;
    text-decoration: none;
    color: #111;
    font-size: 14px;
}
.content {
    padding: 30px;
}
.hero {
    background: #fafafa;
    padding: 24px;
    border-radius: 12px;
    border: 1px solid #eee;
}
.kicker {
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 11px;
    color: #666;
}
.lead {
    margin-top: 10px;
    color: #444;
}
.grid {
    display: grid;
    gap: 12px;
    margin: 20px 0;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}
.tile {
    background: white;
    padding: 16px;
    border-radius: 10px;
    border: 1px solid #eee;
}
.cta {
    background: #111;
    color: white;
    border: none;
    padding: 10px 18px;
    border-radius: 6px;
    cursor: pointer;
}
.footer {
    padding: 18px 30px;
    border-top: 1px solid #eee;
    font-size: 12px;
    color: #666;
}

Output

What Is the Next.js Online Compiler?

The Next.js Online Compiler lets you write and run Next.js-style React patterns directly in your browser with instant preview. It uses Babel to transpile your JSX and renders components with React 18. You get a split-pane editor with a JSX panel for page and layout code, a CSS panel for styling, and a live output iframe. React Hooks, layout composition, and page-level component patterns are supported so you can prototype Next.js application structures without any local setup.

How It Works

Write your JSX page and layout component code in the left-hand editor panel.
Add any CSS styles in the CSS editor below the JSX panel.
Click the Run button in the header toolbar.
The preprocessor handles React and ReactDOM imports automatically, stripping import statements and mapping them to CDN globals.
Babel standalone compiles your JSX into plain JavaScript in the browser.
React 18 and ReactDOM load via CDN inside a sandboxed iframe and render your components in the output preview.

Step-by-Step Example

Follow these steps to create a Next.js-style page with a layout wrapper:

In the JSX editor, define a RootLayout function component that renders a header with navigation, a {children} slot for page content, and a footer.
Define a Page function component that returns a hero section with a title, description, and a grid of feature cards using .map().
Use ReactDOM.createRoot to mount <RootLayout><Page /></RootLayout> into the root element.
In the CSS editor, style the shell layout, topbar, hero section, grid tiles, and footer.
Click Run to compile and render. The full page layout appears in the output panel with header, content area, and footer.

Use Cases

Learning Next.js patterns — Practice layout composition, page structure, and component hierarchy used in Next.js applications.
Prototyping pages — Quickly build and iterate on page layouts and component designs before adding them to a real Next.js project.
Testing React 18 — Experiment with React 18 features like hooks, concurrent patterns, and JSX in an isolated environment.
Sharing demos — Write self-contained React page examples to share with colleagues or in tutorials and documentation.
Teaching — Demonstrate layout patterns, component composition, and React concepts with zero environment setup.

Limitations & Notes

This is not a real Next.js server. It runs React 18 patterns in the browser without a Node.js backend.
Server components, server-side rendering, and streaming are not available.
File-based routing and the Next.js App Router are not supported.
API routes require a server backend and cannot be used here.
No npm package installation is available. Only React and ReactDOM are loaded via CDN.
TypeScript is not supported. Write plain JSX in the editor.
API calls and fetch requests from the iframe may be blocked by CORS policies.

Frequently Asked Questions

Is this a real Next.js server?

No, this is a browser-based sandbox that runs React 18 patterns inspired by Next.js. There is no real Next.js server or build process.

Are server components supported?

No, this is a client-only environment. Server components require a Node.js runtime which is not available here.

Does routing work?

No, file-based routing and the Next.js App Router are not available. This is a single-page component playground.

Can I use API routes?

No, API routes require a Node.js server backend which is not available in this browser-based environment.

Can I use React hooks?

Yes, all React 18 hooks including useState, useEffect, useRef, useMemo, and useCallback are fully supported.

How are imports handled?

React and ReactDOM imports are auto-handled. The compiler strips React import statements and maps them to the global CDN-loaded libraries.

Does this support TypeScript?

No, write plain JSX. Use the TypeScript compiler for TypeScript code.

Can I save my code?

No, code is not saved between sessions. Copy your code before leaving the page.

Sources & References

Next.js official documentation — Official guides, API reference, and tutorials for Next.js.
React official documentation — Official guides and API reference for React 18.
Next.js learn tutorial — Interactive step-by-step tutorial for learning Next.js.
Vercel documentation — Deployment and platform documentation for Next.js applications.
MDN JavaScript — Comprehensive JavaScript language reference.

Next.js Compiler