How to view an HTML file online
- Drop the
.htmlor.htmfile onto the box above, or click it and choose the file. On a phone, pick it from Files or Downloads. - The page renders immediately below. Use Phone, Tablet and Desktop to check how it behaves at each width, or Full screen to see it edge to edge.
- Open Show / edit the HTML code to read or change the source — the view updates as you type.
The file is read by your browser with the File API and rendered in a sandboxed frame. It is never uploaded, so this viewer is safe for private documents, exported reports and email templates.
Is it safe to open an unknown HTML file?
An HTML file can contain JavaScript, and a malicious one opened directly from your downloads folder runs with the permissions of a local file. Here it runs inside a sandboxed iframe that cannot read this site's cookies or storage, cannot navigate this tab, and has no access to other files on your computer. That makes this viewer a sensible way to look inside an attachment you are unsure about. It is still a web page, though — do not type passwords into a form inside a file someone sent you.
Why the page looks different from the original
- Missing images and styles. If the HTML loads
style.cssorimg/photo.jpgfrom its own folder, those files were not part of the single file you opened. Upload the folder as a ZIP with the ZIP to URL converter to see it complete. - Saved web pages. "Save page as → HTML only" keeps the markup but not the assets; "Web page, complete" saves a folder next to the file.
- Email HTML. Email templates are designed for mail clients, which ignore some CSS. Browsers show them more generously than Outlook will.
HTML viewer apps vs an online viewer
On Android and iPhone, dedicated "HTML viewer" apps mostly show the source code. An online viewer renders the page instead, needs no install and works the same on every device. If you need someone else to see the page, a viewer is not enough — publish it as a URL with Publish as URL and send them the link.