diff --git a/tools/editor-tools/src/features/exporter/components/preview-grid.ts b/tools/editor-tools/src/features/exporter/components/preview-grid.ts
index a812da7a..ee73a71d 100644
--- a/tools/editor-tools/src/features/exporter/components/preview-grid.ts
+++ b/tools/editor-tools/src/features/exporter/components/preview-grid.ts
@@ -160,7 +160,7 @@ const PreviewPageCard = (
     img({
       class: "preview-page-image",
       src: page.imageData,
-      alt: `Page ${page.pageNumber}`,
+      alt: `Page ${page.pageNumber + 1}`,
       loading: "lazy",
       style: thumbnailStyle,
     }),
@@ -168,7 +168,7 @@ const PreviewPageCard = (
       {
         class: "preview-page-number",
       },
-      `${page.pageNumber}`,
+      `${page.pageNumber + 1}`,
     ),
   );
 };
diff --git a/tools/editor-tools/src/features/exporter/types.ts b/tools/editor-tools/src/features/exporter/types.ts
index 77106432..c60f703d 100644
--- a/tools/editor-tools/src/features/exporter/types.ts
+++ b/tools/editor-tools/src/features/exporter/types.ts
@@ -24,7 +24,7 @@ export interface ExportFormat {
 }
 
 export interface PreviewPage {
-  pageNumber: number;
+  pageNumber: number; // zero-based
   imageData: string; // base64 encoded PNG
 }