diff --git a/lib/collection-cards-csv.js b/lib/collection-cards-csv.js
new file mode 100644
index 0000000..42aeb5e
--- /dev/null
+++ b/lib/collection-cards-csv.js
@@ -0,0 +1,66 @@
+/**
+ * Build and trigger a browser download of collection cards as CSV.
+ */
+export function downloadCollectionCardsCsv(cards, collectionName) {
+  if (cards.length === 0) {
+    alert('No cards to download');
+    return;
+  }
+
+  const headers = [
+    'Name',
+    'Set Name',
+    'Set Code',
+    'Card Number',
+    'Rarity',
+    'Game',
+    'Mana Cost',
+    'CMC',
+    'Type',
+    'Colors',
+    'Oracle Text',
+    'Power',
+    'Toughness',
+    'Market Price',
+    'Quantity',
+    'Added Date',
+  ];
+
+  const csvRows = [
+    headers.join(','),
+    ...cards.map((card) =>
+      [
+        `"${(card.name || '').replace(/"/g, '""')}"`,
+        `"${(card.set_name || '').replace(/"/g, '""')}"`,
+        `"${card.set_code || ''}"`,
+        `"${card.card_number || ''}"`,
+        `"${card.rarity || ''}"`,
+        `"${card.game || ''}"`,
+        `"${card.mana_cost || ''}"`,
+        `"${card.cmc || ''}"`,
+        `"${card.card_type || ''}"`,
+        `"${Array.isArray(card.colors) ? card.colors.join(', ') : card.colors || ''}"`,
+        `"${(card.oracle_text || '').replace(/"/g, '""')}"`,
+        `"${card.power || ''}"`,
+        `"${card.toughness || ''}"`,
+        `"${card.market_price || ''}"`,
+        `"${card.quantity || 1}"`,
+        `"${card.created_at ? new Date(card.created_at).toLocaleDateString() : ''}"`,
+      ].join(',')
+    ),
+  ];
+
+  const csvContent = csvRows.join('\n');
+  const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
+  const link = document.createElement('a');
+
+  if (link.download !== undefined) {
+    const url = URL.createObjectURL(blob);
+    link.setAttribute('href', url);
+    link.setAttribute('download', `${collectionName || 'collection'}_cards.csv`);
+    link.style.visibility = 'hidden';
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+  }
+}
diff --git a/pages/collection/[identifier].js b/pages/collection/[identifier].js
index af9d411..58c3301 100644
--- a/pages/collection/[identifier].js
+++ b/pages/collection/[identifier].js
@@ -12,6 +12,7 @@ import { ManaCost, ColorFilterSymbol } from '../../components/ManaSymbols';
 import ManaSymbolSettings from '../../components/ManaSymbolSettings';
 import { useAuth } from '../../lib/use-auth';
 import { VOCAB, collectionDisplayName } from '../../lib/collection-vocabulary.js';
+import { downloadCollectionCardsCsv } from '../../lib/collection-cards-csv.js';
 
 export default function CollectionView() {
   const router = useRouter();
@@ -424,68 +425,7 @@ export default function CollectionView() {
   };
 
   const handleDownloadCSV = () => {
-    if (cards.length === 0) {
-      alert('No cards to download');
-      return;
-    }
-
-    // Create CSV headers
-    const headers = [
-      'Name',
-      'Set Name',
-      'Set Code',
-      'Card Number',
-      'Rarity',
-      'Game',
-      'Mana Cost',
-      'CMC',
-      'Type',
-      'Colors',
-      'Oracle Text',
-      'Power',
-      'Toughness',
-      'Market Price',
-      'Quantity',
-      'Added Date'
-    ];
-
-    // Create CSV rows
-    const csvRows = [
-      headers.join(','), // Header row
-      ...cards.map(card => [
-        `"${(card.name || '').replace(/"/g, '""')}"`,
-        `"${(card.set_name || '').replace(/"/g, '""')}"`,
-        `"${card.set_code || ''}"`,
-        `"${card.card_number || ''}"`,
-        `"${card.rarity || ''}"`,
-        `"${card.game || ''}"`,
-        `"${card.mana_cost || ''}"`,
-        `"${card.cmc || ''}"`,
-        `"${card.card_type || ''}"`,
-        `"${Array.isArray(card.colors) ? card.colors.join(', ') : (card.colors || '')}"`,
-        `"${(card.oracle_text || '').replace(/"/g, '""')}"`,
-        `"${card.power || ''}"`,
-        `"${card.toughness || ''}"`,
-        `"${card.market_price || ''}"`,
-        `"${card.quantity || 1}"`,
-        `"${card.created_at ? new Date(card.created_at).toLocaleDateString() : ''}"`
-      ].join(','))
-    ];
-
-    // Create and download the CSV file
-    const csvContent = csvRows.join('\n');
-    const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
-    const link = document.createElement('a');
-    
-    if (link.download !== undefined) {
-      const url = URL.createObjectURL(blob);
-      link.setAttribute('href', url);
-      link.setAttribute('download', `${collection.name || 'collection'}_cards.csv`);
-      link.style.visibility = 'hidden';
-      document.body.appendChild(link);
-      link.click();
-      document.body.removeChild(link);
-    }
+    downloadCollectionCardsCsv(cards, collection?.name);
   };
 
   // Group cards by game