HTML Viewer & Live Preview
Paste or upload HTML and watch it render instantly in a sandboxed, script-free preview.
<iframe> with sandbox="allow-same-origin" — scripts never run, so it's safe to paste HTML from an email, a scraped page, or any untrusted source.Looking for entity encoding instead? Try the HTML Entity Encoder & Decoder.
Your Data Never Leaves Your Device
Every tool runs entirely in your browser. Nothing you type is uploaded, stored, or logged on our servers.
The HTML Viewer is a free, client-side tool that renders HTML markup live as you type. Paste markup on the left and watch it render on the right in a sandboxed preview — no server round-trip, no script execution.
Unlike an HTML formatter, this tool's job is to show you what the markup actually looks like once it's rendered. The preview runs in an <iframe> with scripts blocked, so it's safe to drop in HTML from an email template, a scraped page, or any source you don't fully trust. Switch between mobile, tablet, and desktop viewport widths to check how the layout responds, or jump straight to the HTML formatter to clean up the markup first.
FAQ
No, deliberately. The preview renders inside an <iframe sandbox="allow-same-origin"> without the allow-scripts permission, so <script> tags, inline event handlers like onclick, and javascript: URLs are all blocked. Only HTML and CSS render.
Yes — that's the main reason to use this tool over pasting HTML into a scratch file and opening it directly. Since scripts can't execute, you can safely preview markup copied from an email, a scraped page, or any source you don't fully trust.
Yes, paste the HTML and it will render here. Keep in mind that real email clients (Outlook, Gmail, Apple Mail) each apply their own CSS restrictions, so this preview is a good sanity check but not a substitute for testing in an actual email client.
No. Everything — typing, file uploads, and the preview itself — happens entirely in your browser. Nothing is sent to a server.
Interactive behavior driven by JavaScript is intentionally disabled in the sandboxed preview. Only static rendering (layout, text, images, inline CSS) is shown.