HTML Viewer — Preview HTML
Paste HTML and see it rendered instantly, in a fully isolated preview panel — unlike a formatter, this doesn't change your code: it shows it exactly as a browser would.
Preview security
The HTML is never executed in Numelto's own context: the preview lives inside an <iframe sandbox="">, without the "allow-scripts" permission — the browser guarantees no <script> ever runs, no matter what HTML was pasted, and that iframe can't access this page or your data. As an extra layer, the HTML is also sanitized before being shown.
When to use it
Useful for quickly checking how an HTML fragment looks without creating a file or opening an editor, for reviewing HTML another tool generated, or for debugging an email template or a snippet before using it on a real site.
If what you need is to format the code (indent it), use the HTML formatter.