diff --git a/tldr-summarizer.user.js b/tldr-summarizer.user.js
index 08b2988..876ff84 100644
--- a/tldr-summarizer.user.js
+++ b/tldr-summarizer.user.js
@@ -351,6 +351,10 @@ Summary:`;
 
     function injectFBBtn(article) {
         if (article.dataset.tldrDone) return;
+
+        // Skip comments — they are articles nested inside another article
+        if (article.parentElement && article.parentElement.closest('[role="article"]')) return;
+
         article.dataset.tldrDone = '1';
 
         const text = extractFBText(article);
@@ -371,8 +375,13 @@ Summary:`;
         }
     }
 
+    // Debounced scan — runs at most once per 600ms to avoid hammering the DOM
+    let scanTimer = null;
     function scanFB() {
-        document.querySelectorAll('div[role="article"]').forEach(injectFBBtn);
+        clearTimeout(scanTimer);
+        scanTimer = setTimeout(() => {
+            document.querySelectorAll('div[role="article"]').forEach(injectFBBtn);
+        }, 600);
     }
 
     // ── General articles / pages ──────────────────────────────────────────────