Free Online HTML Viewer

An HTML viewer renders pasted markup live in a sandboxed iframe so you can preview a snippet's layout and styling without saving, uploading or running its scripts.

Your data is processed entirely in your browser and never sent to any server.

Instant results 100% private No signup needed

Scripts are blocked by the sandbox. Some cross-origin images, fonts and stylesheets may not load.

How to Use This Tool

  1. Paste your HTML into the source editor on the left.
  2. Watch the sandboxed preview on the right render it in real time.
  3. Adjust the markup and the preview updates as you type.
  4. Note that scripts are blocked and some cross-origin resources may not load.

What Is a HTML Viewer?

An HTML viewer takes a fragment of markup and paints it the way a browser would, using the parsing rules defined by the WHATWG HTML Living Standard. Because the parser is forgiving, even incomplete snippets — a stray div, an unclosed list — still render, which makes a viewer handy for sanity-checking copied code.

This tool loads your markup into an iframe carrying the sandbox attribute. Per the HTML spec, a bare sandbox blocks script execution, form submission and same-origin access, so pasted code is displayed, not trusted. You see fonts, colors, tables and images exactly as they would appear, but an injected <script> stays inert.

Developers use it to preview email templates and CMS output, writers check how a block of formatted content looks, and students learn by pasting examples and watching them render. Everything happens in your browser through a data URL, so nothing is transmitted and closing the tab clears it all.

Frequently Asked Questions

Does the viewer run JavaScript in pasted markup?
No. The preview frame uses a sandbox attribute that blocks scripts, so you see the layout and styling without any code executing.
Will external images and stylesheets load?
Absolute URLs that allow cross-origin requests usually load; relative paths and resources behind CORS restrictions may not appear.
Is my markup sent anywhere?
No. Rendering happens entirely in your browser using a data-URL frame. Closing the tab discards everything.

Published by the WeGotEveryTool team. We build and test every tool in-house and update pages when the underlying spec, formula, or recommendation changes.

Reviewed: May 2026. Disclaimer: this tool is provided as-is for general informational use. For decisions with material consequences (medical, legal, financial, security) verify results against a qualified professional source.

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