HTML Viewer
Render HTML in a sandboxed live preview as you type. It runs entirely on your device — nothing is uploaded.
Example
Paste HTML to see it rendered instantly in a sandboxed preview.
How it works
Your HTML is rendered in a sandboxed iframe so you can preview it safely without leaving the page.
Good to know
HTML Viewer turns raw HTML markup into a live rendered preview the instant you type or paste it. Instead of saving a file, opening it in a browser, and refreshing on every change, you get an immediate visual of how your tags, structure, and inline styles actually display. It is built for front-end developers, students learning markup, technical writers checking email or CMS snippets, and anyone who receives a chunk of HTML and just wants to see what it looks like.
Reach for it when you copy a code block from documentation, a Stack Overflow answer, an AI assistant, or an exported email template and need to confirm it renders before committing it anywhere. It is also handy for quick experiments — testing how a table, form, or list nests, or sanity-checking a snippet on a locked-down machine where you cannot install an editor. Because the preview runs in a sandboxed iframe entirely on your device, you can paste sensitive or proprietary markup without it being uploaded anywhere.
Read the result as a faithful but isolated render: what you see is how a browser interprets your markup with its default styles plus whatever inline CSS you included. Keep these points in mind when interpreting it:
- External stylesheets, fonts, and scripts may be blocked by the sandbox, so a snippet can look plainer here than on a fully loaded site.
- Relative paths to images or assets will not resolve — use absolute URLs to preview media.
- The viewer shows rendering, not correctness, so malformed or unclosed tags may still display because browsers auto-correct them.
A practical tip: if your goal is to clean up messy markup rather than just see it, pair this with an HTML Formatter or Validator — the viewer confirms appearance, while those tools catch indentation and syntax problems the preview will silently forgive.
Frequently asked questions
Is my data uploaded anywhere?
No — everything runs in your browser. Your code never leaves your device, so it's safe for private work and runs offline once loaded.
Is this tool free?
Yes, completely free with no sign-up and no limits.
People also ask
What is the difference between an HTML viewer and an HTML editor?
An HTML viewer focuses on rendering markup so you can see the visual output, while an HTML editor adds tools for writing and modifying code such as syntax highlighting, autocomplete, and error hints. Many viewers let you type too, but their main purpose is the live preview rather than authoring.
Why does my HTML look different in the viewer than on my live website?
A sandboxed viewer often blocks or omits external CSS, web fonts, and JavaScript, so it shows mainly your markup with browser default styles and inline CSS. Your live site loads those external resources, which changes the appearance.
Can I preview HTML with CSS and JavaScript included?
Inline CSS in <style> tags and inline styles usually render in the preview. JavaScript and external resources may be limited by the iframe sandbox for security, so interactive scripts might not run.
Does an HTML viewer validate my code or check for errors?
No, a viewer renders markup the way a browser would, and browsers automatically correct many mistakes like unclosed tags. To catch syntax issues you would use a dedicated HTML validator instead.
Is it safe to paste private or confidential HTML into an online viewer?
It depends on the tool. A client-side viewer that runs entirely in your browser does not upload your code, so the markup stays on your device, but you should verify any tool's privacy claims before pasting sensitive content.
Will images and links work in the HTML preview?
Links and images referenced with absolute URLs generally display, but relative paths pointing to local files or site folders will not resolve in an isolated preview. Use full https URLs to see media render.
Can I use an HTML viewer offline?
A purely client-side tool can keep working after it has loaded, since the rendering happens in your browser rather than on a server. You would still need an initial load while connected to the internet.
How do I quickly test an HTML email template?
Paste the template's HTML into a viewer to check the layout and inline styles, since email markup relies heavily on inline CSS and tables. Keep in mind that real email clients vary widely, so a preview is an approximation rather than a guarantee.
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