diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index c7239a4..bcefc73 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -23,6 +23,7 @@ import { Splitter } from "./Splitter";
 import { SettingsDialog, DEFAULT_TITLE } from "./SettingsDialog";
 import { pendingVersion, useUpdateStatus } from "./update";
 import { storeThumb } from "./thumbs";
+import { fitScene } from "./fit";
 
 type Theme = "light" | "dark";
 type SaveState = "saved" | "dirty" | "saving" | "error";
@@ -105,6 +106,7 @@ export default function App() {
   const libTimer = useRef<number>(undefined);
   const libJson = useRef(""); // dernier état connu côté serveur
   const sceneSeq = useRef(0);
+  const fitPending = useRef(false); // cadrage à faire au premier rendu du schéma ouvert
   const exTheme = useRef<string | null>(null); // dernier thème signalé par Excalidraw
   const openRef = useRef<(path: string, opts?: { skipFlush?: boolean }) => Promise<void>>(async () => {});
 
@@ -169,6 +171,10 @@ export default function App() {
         if (appState.theme !== theme) setTheme(appState.theme as Theme);
       }
       if (!pathRef.current || appState.isLoading) return;
+      if (fitPending.current && excalidraw.current) {
+        fitPending.current = false;
+        fitScene(excalidraw.current);
+      }
       const version = sceneVersion(elements, appState, files);
       // Premier onChange après chargement : c'est la version de référence.
       if (savedVersion.current === "") {
@@ -195,6 +201,7 @@ export default function App() {
         etagRef.current = etag;
         savedVersion.current = ""; // fixée au premier onChange (voir onChange)
         pathRef.current = path;
+        fitPending.current = true;
         setScene({
           id: ++sceneSeq.current,
           path,
@@ -202,7 +209,6 @@ export default function App() {
             elements: data.elements ?? [],
             appState: { ...(data.appState ?? {}), theme },
             files: data.files ?? {},
-            scrollToContent: true,
           },
         });
         setSaveState("saved");
diff --git a/frontend/src/ShareView.tsx b/frontend/src/ShareView.tsx
index 36b1a2e..8f2be84 100644
--- a/frontend/src/ShareView.tsx
+++ b/frontend/src/ShareView.tsx
@@ -1,8 +1,9 @@
-import { useEffect, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { Excalidraw } from "@excalidraw/excalidraw";
-import type { ExcalidrawInitialDataState } from "@excalidraw/excalidraw/types";
+import type { AppState, ExcalidrawImperativeAPI, ExcalidrawInitialDataState } from "@excalidraw/excalidraw/types";
 import { api, type PublicScene } from "./api";
 import { DEFAULT_TITLE } from "./SettingsDialog";
+import { fitScene } from "./fit";
 import { DownloadIcon, EyeIcon, MoonIcon, SunIcon } from "./icons";
 
 type Theme = "light" | "dark";
@@ -22,6 +23,21 @@ export function ShareView({ token }: { token: string }) {
   const [data, setData] = useState<PublicScene | null>(null);
   const [error, setError] = useState<string | null>(null);
   const [theme, setTheme] = useState<Theme>(initialTheme);
+  const excalidraw = useRef<ExcalidrawImperativeAPI | null>(null);
+  const fitted = useRef(false);
+
+  const onApi = useCallback((ex: ExcalidrawImperativeAPI | null) => {
+    excalidraw.current = ex;
+  }, []);
+  // excalidrawAPI jusqu'à la 0.18, onExcalidrawAPI sur le canal next.
+  const apiProps = { excalidrawAPI: onApi, onExcalidrawAPI: onApi } as object;
+
+  // Premier rendu : cadrage sur l'ensemble du schéma.
+  const onChange = useCallback((_elements: unknown, appState: AppState) => {
+    if (appState.isLoading || fitted.current || !excalidraw.current) return;
+    fitted.current = true;
+    fitScene(excalidraw.current);
+  }, []);
 
   useEffect(() => {
     api
@@ -51,7 +67,6 @@ export function ShareView({ token }: { token: string }) {
     elements: (data.scene.elements ?? []) as ExcalidrawInitialDataState["elements"],
     appState: { ...(data.scene.appState ?? {}), theme } as ExcalidrawInitialDataState["appState"],
     files: (data.scene.files ?? {}) as ExcalidrawInitialDataState["files"],
-    scrollToContent: true,
   };
 
   return (
@@ -96,6 +111,8 @@ export function ShareView({ token }: { token: string }) {
           <Excalidraw
             initialData={initialData}
             viewModeEnabled
+            {...apiProps}
+            onChange={onChange}
             theme={theme}
             langCode="fr-FR"
             name={data!.name}
diff --git a/frontend/src/fit.ts b/frontend/src/fit.ts
new file mode 100644
index 0000000..0809e5f
--- /dev/null
+++ b/frontend/src/fit.ts
@@ -0,0 +1,22 @@
+import type { ExcalidrawImperativeAPI } from "@excalidraw/excalidraw/types";
+
+const isMobile = () => window.matchMedia("(max-width: 768px)").matches;
+
+/**
+ * Cadre tout le schéma dans la zone visible, sans zoomer au-delà de 100 %.
+ *
+ * Remplace `initialData.scrollToContent` : quand le contenu déborde de la
+ * fenêtre, Excalidraw centre alors un seul élément (le plus proche de l'origine)
+ * au lieu de l'ensemble, et le schéma s'affiche à partir du milieu de l'écran.
+ */
+export function fitScene(ex: ExcalidrawImperativeAPI) {
+  const elements = ex.getSceneElements();
+  if (elements.length === 0) return;
+  ex.scrollToContent(elements, {
+    fitToContent: true,
+    viewportZoomFactor: 0.9,
+    animate: false,
+    // Barres d'outils d'Excalidraw posées sur le canevas (en haut, et en bas sur mobile).
+    canvasOffsets: { top: 64, bottom: isMobile() ? 64 : 0 },
+  });
+}