HTML Viewer
Preview HTML live in a secure sandboxed frame while you edit the source.
About the HTML Viewer
The HTML Viewer renders your markup live as you edit it, inside a sandboxed frame that cannot reach the rest of the site, so you can preview snippets, emails or templates safely.
Everything runs in your browser, so your input is never uploaded to a server.
How to use the HTML Viewer
- Paste or type HTML in the editor.
- Watch the preview update as you type.
- Switch on "Run scripts" only if your snippet needs JavaScript.
Frequently asked questions
Is it safe to preview untrusted HTML?
Yes. The preview runs in a sandboxed iframe with no access to this page, and scripts stay disabled unless you switch them on.
Why does an external script not load?
The site's security policy blocks scripts from other domains. Inline scripts run when "Run scripts" is on.
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