HTML Editor with Preview and Console: free html viewer online

CodeMirror editor with real preview

This page is no longer a basic viewer only. It is an HTML playground with CodeMirror tabs for HTML, CSS, and JavaScript, syntax highlighting, line numbers, lint gutter, and a sandboxed iframe preview.

The workflow is designed for developers, creators, and students who need to test snippets, components, landing sections, forms, tables, or HTML email layouts without opening a full IDE.

Captured console, simple checks, and templates

The console captures console.log, console.warn, console.error, runtime errors, and rejected promises from inside the preview. That makes it easier to see whether a snippet is actually running.

The tool also includes simple checks for possibly unclosed HTML tags, CSS braces, and JavaScript syntax. Quick templates cover starter components, landing sections, HTML email, forms, and tables.

• Edit HTML, CSS, and JS in dedicated tabs.
• Run preview manually or with auto-run.
• Capture iframe logs and errors in the tool console.
• Use templates and export the final HTML file.

Files, responsive preview, and export

If your code is split across files, upload .html, .css, and .js files to populate the editor. The selected HTML entry is rendered with the combined CSS and JavaScript bundle.

Desktop, tablet, and mobile preview widths help you check responsive behavior. You can copy the final document, download a complete .html file, open the preview in a new tab, or switch to fullscreen.

Safety and practical limits

Scripts execute inside a sandboxed iframe preview. Run trusted code only when testing external snippets.

For larger test setups, opening preview in a new tab can improve screen usage and debugging comfort.