Question 1

What is an online HTML viewer?

Accepted Answer

An HTML viewer lets you paste or type HTML markup and instantly see how it renders in a browser — without creating a file, setting up a server or writing a full web page. It is perfect for testing snippets, debugging layouts, previewing HTML emails and learning HTML.

Question 2

Is the HTML viewer safe?

Accepted Answer

Yes. The HTML is rendered inside a sandboxed iframe on your own device. Scripts run only inside the sandbox — they cannot access the parent page, your cookies, your filesystem or any server. Your HTML never leaves your browser.

Question 3

Can I test JavaScript in the HTML viewer?

Accepted Answer

Yes. <script> tags execute inside the sandboxed iframe. You can test interactive snippets, animations and small widgets. Network requests via fetch follow the browser's normal CORS rules. To disable scripts entirely, untick the Allow scripts option.

Question 4

How is this different from the HTML/CSS/JS Code Editor?

Accepted Answer

The Code Editor gives you three separate panels for HTML, CSS and JS. The HTML Viewer is simpler — it renders a single HTML document (which can include inline

Question 5

Can I preview HTML emails?

Accepted Answer

Yes. Paste your table-based email HTML and see how it renders. The viewer is great for checking whether an email template looks right before you send it. Use the responsive width buttons to simulate mobile and desktop clients.