🌐 HTML Viewer

Paste any HTML snippet and instantly render it in a sandboxed iframe — or view it as raw source code. Useful for previewing emails, debugging templates, and learning HTML.

What is the html viewer?

An HTML viewer lets you see what a chunk of HTML looks like rendered, without having to save it as a file and open it in a browser. Particularly useful for transactional emails (where you have the HTML but not a place to render it), Stack Overflow answers, CMS template fragments, and scraped HTML you want to inspect.

How does this html viewer work?

Paste HTML into the textarea. Click Render to see it in a sandboxed iframe inside the page. Click View Source to see the same HTML as syntax-coloured source code. The iframe is sandboxed so any embedded JavaScript runs safely without affecting this site.

When should you use this tool?

Use it when previewing transactional or marketing emails before sending, when learning HTML by experimenting with snippets, when debugging a CMS template, when inspecting scraped HTML, and when sharing HTML demos with colleagues over chat.

Tips & best practices

For full email testing use a service like Litmus or Email on Acid — they render in actual mail clients (Outlook, Gmail, Apple Mail) which behave differently from browsers. For HTML-to-PDF rendering use Puppeteer or wkhtmltopdf. For modern responsive testing, also check the rendered output in DevTools mobile mode.

Frequently asked questions

Does the iframe execute JavaScript?

Yes, but it runs in a sandboxed iframe so it can't access this page or your cookies.

Can I save the rendered output as PDF?

Use your browser's Print → Save as PDF on the rendered iframe.

Why does my email look different in Gmail?

Email clients have wildly different CSS support. Always test in real clients before sending campaigns.

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