diff --git a/js/social-threads.js b/js/social-threads.js
index 1a84836..9756522 100644
--- a/js/social-threads.js
+++ b/js/social-threads.js
@@ -97,6 +97,13 @@ document.addEventListener("alpine:init", () => {
           published: s.created_at,
           favourites: s.favourites_count || 0,
         }));
+
+        // Remove webmention cards (build-time or client-fetched) that duplicate mastodon replies.
+        // Webmention cards have data-author-url; Alpine x-for cards do not.
+        const mastodonAuthorUrls = new Set(this.mastodonReplies.map((r) => r.author.url));
+        document.querySelectorAll(".webmention-replies li[data-author-url]").forEach((li) => {
+          if (mastodonAuthorUrls.has(li.dataset.authorUrl)) li.remove();
+        });
       } catch {
         // fail silently
       }