diff --git a/apps/playground/src/app/page.tsx b/apps/playground/src/app/page.tsx
index 35b18eb..45fe32c 100755
--- a/apps/playground/src/app/page.tsx
+++ b/apps/playground/src/app/page.tsx
@@ -26,6 +26,7 @@ import {
   type FileInfo,
   type FileType,
   type HtmlTrustedPreviewRequest,
+  type PreviewSizePolicyConfig,
   detectFileType,
   detectFileMeta,
   PluginPreviewRenderer,
@@ -52,6 +53,14 @@ setAssetBasePath(process.env.NEXT_PUBLIC_BASE_PATH || "");
 // (PDF, DOCX, PPTX, XLSX, RTF, ZIP, EPUB and base formats).
 const previewRegistry = createFullPreviewRegistry();
 
+// Playground-only limit. Library consumers retain the default 20/50/100 MB policy.
+const MB = 1024 * 1024;
+const DEMO_PREVIEW_POLICY = {
+  warningBytes: 20 * MB,
+  confirmBytes: 35 * MB,
+  maxBytes: 50 * MB,
+} satisfies PreviewSizePolicyConfig;
+
 const FILE_TYPE_ICONS: Record<FileType, string> = {
   pdf: "📄",
   markdown: "📝",
@@ -238,6 +247,7 @@ export default function Home() {
     try {
       const info = await processRemoteUrl(currentUrl, {
         signal: controller.signal,
+        maxBytes: DEMO_PREVIEW_POLICY.maxBytes,
         onProgress: setRemoteProgress,
       });
 
@@ -416,6 +426,9 @@ export default function Home() {
               onChange={handleFileInput}
               accept="*"
             />
+            <p className="text-center text-[11px] text-muted-foreground">
+              Preview files up to 50 MB each
+            </p>
             <div className="flex gap-2">
               <input
                 value={remoteUrl}
@@ -596,20 +609,14 @@ export default function Home() {
                 </div>
               )}
 
-              {/* Preview content — PluginPreviewRenderer applies its own
-                  LargeFileGate. Thresholds are tuned for the demo: warn at
-                  2 MB, require confirmation at 3 MB, block at 5 MB. */}
+              {/* Preview content — the Demo gates files at 20/35/50 MB. */}
               <div className="flex-1 min-h-0 min-w-0">
                 <PluginPreviewRenderer
                   file={activeFile}
                   registry={previewRegistry}
                   showPluginDebug={process.env.NODE_ENV === "development"}
                   onHtmlTrustedPreviewRequest={handleTrustedPreviewRequest}
-                  largeFilePolicy={{
-                    warningBytes: 2 * 1024 * 1024,
-                    confirmBytes: 3 * 1024 * 1024,
-                    maxBytes: 5 * 1024 * 1024,
-                  }}
+                  largeFilePolicy={DEMO_PREVIEW_POLICY}
                 />
               </div>
             </>
diff --git a/docs/github-pages-release-checklist.md b/docs/github-pages-release-checklist.md
index ee32458..d17deff 100644
--- a/docs/github-pages-release-checklist.md
+++ b/docs/github-pages-release-checklist.md
@@ -122,20 +122,22 @@ Expected:
 unknown → Preview Not Available
 ```
 
-## 8. Check Large File Hint
+## 8. Check Demo Preview Size Limit (50 MB)
 
-Upload a file >= 20MB of type:
+The **Playground demo** has its own policy: warn at 20 MiB, require confirmation at 35 MiB, and block previews above 50 MiB (50 × 1024 × 1024 bytes). The reusable library retains its default thresholds.
 
-```txt
-PDF / DOCX / PPTX / XLSX / ZIP / EPUB
-```
+Test local PDF / DOCX / PPTX / XLSX / ZIP / EPUB files through both **Browse Files** and drag-and-drop:
 
-Expected:
+| File size | Expected |
+| --- | --- |
+| Less than 20 MiB | Preview normally |
+| 20–under 35 MiB | Show a warning, continue preview |
+| 35–50 MiB (inclusive) | Require explicit confirmation before preview |
+| Greater than 50 MiB | Block local preview and offer download |
 
-```txt
-Large file hint appears
-User can still proceed with preview
-```
+The **remote URL** loader must enforce the same 50 MiB cap before or during download. Verify that a remote file above the limit produces a clear error (subject to CORS). A file exactly 50 MiB must remain eligible for preview.
+
+The limit applies per file, not to the total size of the selected files. Large-file parsing may still be slow or require significant memory even when the size policy allows it.
 
 ## 9. Check Browser Console