Your data
never leaves here.
HTML Viewer Cat runs entirely in your browser. There is no account. There is no server that sees your HTML. Here's exactly what happens to the data you touch.
What we collect
Nothing personally identifiable. We don't ask for your email, name, or account. We don't set tracking cookies — at all. We use Plausible, a privacy-friendly cookieless analytics service, to count anonymized page views and tool actions. No user identifiers, no fingerprinting, no cross-site tracking. Plausible is GDPR-compliant by default and doesn't require a consent prompt because there are no cookies to consent to.
What stays on your device
- The current content of each editor — persisted to
localStorageso you can close a tab and come back. - Split-pane position, theme preference, tool-specific settings (all under the
hvc:*key prefix).
Clearing your browser's storage for this site wipes everything. There is no copy anywhere else.
How share-links work
When you click Share on the HTML Viewer, your HTML is base64-encoded and placed after a #s= fragment in the URL. Browser fragments never get sent to the server. When someone opens your link, their browser decodes the fragment locally — no round-trip to us. That means we genuinely do not have a copy of your paste, even if we wanted one.
Third-party requests
- Google Fonts (JetBrains Mono, Inter, Instrument Serif) — loaded via Next.js so the chrome fonts are self-hosted at build time.
- Plausible Analytics (cookieless, anonymized).
- Any network request your own HTML makes from its sandboxed iframe.
That's it. No ad networks, no session replay, no third-party JS outside of what's listed.
Updates
Last updated 2026-05-01. Material changes will be announced in the changelog.