diff --git a/components/agents/AgentPsdTemplateEditorDialog.tsx b/components/agents/AgentPsdTemplateEditorDialog.tsx
index 5f72f3ef7..eb4dbcd2d 100644
--- a/components/agents/AgentPsdTemplateEditorDialog.tsx
+++ b/components/agents/AgentPsdTemplateEditorDialog.tsx
@@ -54,6 +54,8 @@ import { resolveTextLayout } from "@/lib/agents/psd-text-layout";
 const fetcher = (url: string) => fetch(url, { cache: "no-store" }).then((res) => res.json());
 const PREVIEW_VIEWPORT_PADDING = 56;
 const PREVIEW_STAGE_MAX_SCALE = 0.82;
+const PREVIEW_STAGE_TARGET_WIDTH = 760;
+const PREVIEW_STAGE_TARGET_HEIGHT = 760;
 
 function createInitialState(template: AgentPsdTemplate | null, sourceImageUrl: string) {
   const imageAssignments: Record<string, string> = {};
@@ -477,8 +479,14 @@ export function AgentPsdTemplateEditorDialog({
 
     const updateScale = () => {
       const rect = element.getBoundingClientRect();
-      const availableWidth = Math.max(240, rect.width - PREVIEW_VIEWPORT_PADDING);
-      const availableHeight = Math.max(240, rect.height - PREVIEW_VIEWPORT_PADDING);
+      const availableWidth = Math.max(
+        240,
+        Math.min(PREVIEW_STAGE_TARGET_WIDTH, rect.width - PREVIEW_VIEWPORT_PADDING)
+      );
+      const availableHeight = Math.max(
+        240,
+        Math.min(PREVIEW_STAGE_TARGET_HEIGHT, rect.height - PREVIEW_VIEWPORT_PADDING)
+      );
       const nextScale = Math.min(
         availableWidth / Math.max(1, selectedTemplate.width),
         availableHeight / Math.max(1, selectedTemplate.height),