HTML Viewer & Live Preview
Render raw HTML and code instantly in a secure, isolated sandbox, entirely in your browser.
Related tools
About this tool
This tool renders whatever HTML you type or paste into a live preview pane as you edit it, without sending anything to a server. It's useful for quickly checking how a snippet of markup looks, testing a piece of email HTML, previewing an embed code before you drop it into a CMS, or just experimenting with a layout idea without spinning up a project.
The preview pane is a sandboxed iframe: it runs the HTML you provide in an isolated browsing context with no access to this page, its cookies, or its storage, and it cannot navigate the parent window. Scripts inside your snippet do run, so interactive demos and inline script tags work as expected, but the sandbox keeps that code contained to its own isolated origin.
Because rendering happens entirely inside your browser, nothing you paste is ever uploaded or logged anywhere — the page works fully offline once it's loaded, so you can safely preview markup that includes sensitive text, internal URLs, or work-in-progress content.
This is handy any time you need a quick sanity check on markup: verifying that tags are balanced and elements nest correctly, checking how inline CSS renders, confirming an HTML email template displays as intended before sending it, or reviewing a third-party embed snippet before trusting it on a real page.
Keep in mind this is a preview tool, not a full browser environment — external resources (stylesheets, images, fonts) referenced by URL will still load over the network if your snippet points to them, and scripts run in a restricted, cookie-less context rather than your site's real origin, so anything that depends on your site's actual cookies, local storage, or same-origin requests won't behave identically here.
A typical workflow is simple: type your markup straight into the editor or drop it in with the Paste button, watch the preview refresh on every keystroke, and keep tweaking until the result looks right. The Clear button empties the editor in one click when you want to start over. Markup produced by other tools in this toolbox can also land here directly — for example, decode a Base64-encoded HTML fragment in the Base64 tool and use its "Send to" menu to open the decoded result in this viewer, with no manual copy and paste in between.
Frequently asked questions
Is it safe to preview HTML from an untrusted source here? expand_more
The preview runs in a sandboxed iframe with its own isolated, cookie-less origin, so it can't read this page's data or your site's cookies. Scripts inside the snippet do still execute, though, so treat it the same way you'd treat opening any unfamiliar page — don't paste anything you wouldn't want to run at all.
Does my HTML get uploaded anywhere? expand_more
No. Rendering happens entirely inside your browser, and the tool keeps working offline once the page has loaded.
Will external images, fonts, or stylesheets load in the preview? expand_more
Yes, if your HTML references them by URL, the sandboxed iframe will still fetch them over the network, just like a normal page would.
Do script tags in my snippet actually run? expand_more
Yes, scripts execute inside the sandboxed iframe, which lets you preview interactive demos — but that execution is isolated from this page and from your site's real origin.
Why doesn't a script that reads cookies or localStorage work the same as on my real site? expand_more
The sandboxed iframe has its own unique, isolated origin rather than your site's real one, so it has no access to your site's actual cookies or storage — anything relying on those will behave differently here.