HTML Formatter
Beautify or minify HTML and find unclosed tags, stray closing tags, and duplicate attributes.
HTML Viewer
Paste HTML and see it rendered live in a secure sandbox. Free, private, and 100% in your browser.
HTML Code
1 lines · 0 BPreview
The rendered page will appear here.
Full width · Sandboxed preview · JavaScript off · Offline (no network requests)
Preview HTML Online
An HTML viewer renders HTML code so you can see the result without creating a file or opening a browser tab. It is useful for checking email templates, snippets from documentation, generated reports, and markup you are about to publish.
This viewer renders your code in an isolated sandbox. Scripts and network requests are off unless you turn them on, so previewing a page never runs code or contacts other servers without your permission.
Features
Live preview
The page re-renders as you type, so you see every change right away.
Secure sandbox
The preview runs in an isolated iframe that cannot access this site, your cookies, or other tabs.
Scripts off by default
JavaScript only runs if you enable it, so pasted code cannot do anything unexpected.
Offline by default
External images, stylesheets, fonts, and requests are blocked unless you allow them, so nothing is sent to third parties.
Device widths
Switch between full width, tablet (768px), and mobile (375px) to check responsive layouts.
Private by design
Your HTML is rendered locally in your browser. It is never uploaded.
How to View HTML Online
- Paste your HTML into the editor, or upload or drop an .html file.
- The preview updates automatically as you type.
- Switch between Responsive, Tablet, and Mobile widths.
- Enable JavaScript or external resources only if you need them.
Frequently Asked Questions
Is it safe to preview untrusted HTML here?
The preview runs in a sandboxed iframe with a unique origin, so it cannot read this site's data, your cookies, or other pages. JavaScript is disabled and network access is blocked by default. Only enable them for code you trust.
Why are my images or stylesheets not loading?
To protect your privacy, external resources are blocked by default so that previewing HTML never contacts other servers. Enable Load external resources to load images, CSS, and fonts from the web. Inline styles and data: URLs always work.
Why doesn't my JavaScript run?
Scripts are disabled by default for safety. Enable Run JavaScript to run inline scripts. External script files also need Load external resources.
Can I preview a full HTML file?
Yes. Upload or drop an .html file, or paste a complete document including <!DOCTYPE html>, <head>, and <body>. Relative links to other files on your computer cannot be loaded.
Is my HTML uploaded anywhere?
No. The preview is rendered entirely in your browser. Your HTML never leaves your device.
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