HTML Viewer

Paste HTML and preview it live, side by side, in a safe sandbox. 🔒 Runs in your browser

HTML code
Live preview

The preview runs in an isolated sandbox: it cannot read this site's data or cookies.

How to use the HTML Viewer

  1. Paste your HTML code in the left box, open an .html file, or click "Example".
  2. The preview on the right updates live as you type.
  3. Switch the preview width to check mobile and tablet layouts.
  4. Open the result in a new tab or download it as an .html file.

About this tool

Paste HTML and preview it live, side by side, in a safe sandbox. It is part of the free Developer Tools collection on Online Tools Harbor. Everything happens locally in your browser, so it is fast and private.

Frequently asked questions

Is it safe to run unknown HTML?

The preview runs in an isolated sandbox that cannot access this site, your cookies or other tabs. You can also turn JavaScript off.

Is the HTML Viewer free?

Yes. The HTML Viewer is completely free to use, with no sign-up and no limits on normal use.

Is my data safe?

Yes. This tool runs entirely in your web browser using JavaScript. Your text is never uploaded to our servers.

Does it work on mobile?

Yes, it works in any modern browser on phones, tablets and computers. No app to install.

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