Free HTML Viewer
Paste HTML and preview it instantly. Live rendering in a sandboxed environment. Nothing is uploaded. Your code never leaves your device.
How it works
The editor on the left accepts any HTML. As you type, the preview on the right renders your markup in a sandboxed iframe with a short debounce so it doesn't flicker while you're mid-keystroke.
The iframe uses the sandbox="allow-scripts" attribute. Scripts inside your HTML can run (so you can test interactive behavior), but the iframe cannot access the parent page, cookies, localStorage, or make network requests. This makes it safe to paste untrusted HTML.
Your HTML is rendered using a blob URL that exists only in your browser's memory. Nothing is uploaded or stored.
HTML Viewer FAQ
Is it safe to paste untrusted HTML?
The preview renders inside a sandboxed iframe. The sandbox attribute prevents the pasted HTML from accessing cookies, local storage, or the parent page. Scripts can run inside the preview (so you can test interactive HTML), but they cannot make network requests or access anything outside the iframe.
Does the preview update automatically?
Yes. The preview updates as you type, with a short delay (300ms) to avoid flickering while you're still editing. You can also click the Refresh button to force an immediate update.
Can I preview CSS and JavaScript too?
Yes. Paste a complete HTML document with inline <style> and <script> tags, and the preview renders everything including styles and interactive behavior.
Is my HTML uploaded anywhere?
No. Everything runs locally in your browser. The HTML is rendered using a blob URL that exists only in your browser's memory. Nothing is sent to a server.