How it works
How to use the HTML Viewer
Paste HTML
Or open an .html file.
Edit
The preview updates as you type.
Format or download
Beautify the markup or save the page.
Safe previews
The preview runs in a sandboxed frame: scripts are disabled and external files are blocked, so pasted markup can’t run code or track you.
Built for developers
Why developers use it
Private by design
Runs 100% in your browser. Nothing you paste is uploaded, logged or stored on a server.
Instant results
Output updates as you type, with precise error locations when something is wrong.
Works offline
Once loaded, the tool keeps working without a connection. Install it as an app if you like.
Free, no sign-up
No accounts, no limits, no watermarks.
FAQ
Frequently asked questions
Why don’t my images show?
External resources are blocked for privacy. Inline data: URIs and CSS styles work.
Is my data uploaded anywhere?
No. Everything runs locally in your browser — nothing you paste or open is sent to a server, logged or stored. The tool keeps working offline once the page has loaded.
Keep going
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