Write HTML, CSS, and JavaScript in a split-pane editor with instant live preview and console output.
HTML / CSS / JS Playground places markup, style rules, and browser-side code in separate editing panes, then shows their combined page and console output as you type. It is suited to testing a small interaction or reproducing a front-end issue without creating project files. HTML determines the content, CSS changes its presentation, and JavaScript can modify the page or log values. The usual surprise is scope: this is a browser playground, not a Node.js project runner, so server APIs, installed packages, filesystem access, and build tooling are not supplied.
A concrete input and expected output from the current implementation.
Input
HTML:
<p class="answer">7 x 6 = 42</p>
CSS:
.answer {
color: blue;
font-weight: bold;
}
JavaScript:
console.log(7 * 6); Expected output
Preview: a bold blue line reading "7 x 6 = 42" Console: 42
The HTML supplies the displayed equation, and the CSS makes that paragraph bold and blue. JavaScript evaluates 7 times 6 and sends the numeric result 42 to the console.
Enter each language in its corresponding pane. The preview reflects the three sources together, so an HTML class can be styled by CSS and selected by JavaScript. Names remain case-sensitive where the underlying language requires it; a mismatched id or class often looks like a rendering problem even though the code simply does not connect.
Visual results appear in the live preview, while values sent with console.log appear in the console area. Use the two outputs together: the preview answers what the page renders, and the console exposes intermediate values. A JavaScript syntax error or runtime exception can stop later statements, so an unchanged preview does not necessarily mean the editor ignored the latest code.
No. The playground runs browser-facing HTML, CSS, and JavaScript; it does not provide a Node.js process, package installation, a filesystem, environment variables, or backend endpoints. Browser-ready libraries may work when referenced as external scripts, but that introduces network, version, and browser security dependencies. Code requiring a build step should be built elsewhere first.
No. Editing and previewing happen in the browser, and normal use does not upload the snippet or create a hosted deployment. However, JavaScript you enter can make network requests, and external images, fonts, scripts, stylesheets, or fetch calls contact their referenced servers. Remove secrets before running code that communicates with outside services.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
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