NostrComments is a browser extension that adds a comment section to any website. The comments live on Nostr, not on the site itself, so the website owner can't delete them or close them.

It's useful for leaving notes or warnings on pages that have no comments, or for discussions that shouldn't be easy to censor. No account, no tracking, open source.

Caveats: it's still early, so most pages are empty. And like everything on Nostr, you manage your own key. It works best if you already use Nostr or are curious about it.

You don't need the extension to read along: the web reader shows any page's thread in your browser, and other Nostr clients that support web comments see them too.

Firefox: https://addons.mozilla.org/en-US/firefox/addon/nostrcomments/
Chrome: https://chromewebstore.google.com/detail/nostrcomments/ebmgdpicceaencegknannfaljhbfgido
Read without installing: https://briskness-byte.github.io/thread/