diff --git a/krillnotes-desktop/src-tauri/src/commands/attachments.rs b/krillnotes-desktop/src-tauri/src/commands/attachments.rs
index 53115ba1..79560945 100644
--- a/krillnotes-desktop/src-tauri/src/commands/attachments.rs
+++ b/krillnotes-desktop/src-tauri/src/commands/attachments.rs
@@ -239,3 +239,37 @@ pub async fn open_attachment(
         .open_path(tmp_path.to_string_lossy().as_ref(), None::<&str>)
         .map_err(|e: tauri_plugin_opener::Error| e.to_string())
 }
+
+const DEFAULT_ATTACHMENT_MAX_SIZE_MB: u64 = 10;
+
+#[tauri::command]
+pub async fn get_attachment_max_size_mb(
+    window: tauri::Window,
+    state: tauri::State<'_, crate::AppState>,
+) -> Result<u64, String> {
+    let workspaces = state.workspaces.lock().map_err(|e| e.to_string())?;
+    let ws = workspaces
+        .get(window.label())
+        .ok_or_else(|| "No workspace open".to_string())?;
+    let bytes = ws.attachment_max_size_bytes().map_err(|e| e.to_string())?;
+    Ok(bytes
+        .map(|b| b / (1024 * 1024))
+        .unwrap_or(DEFAULT_ATTACHMENT_MAX_SIZE_MB))
+}
+
+#[tauri::command]
+pub async fn set_attachment_max_size_mb(
+    window: tauri::Window,
+    state: tauri::State<'_, crate::AppState>,
+    limit_mb: u64,
+) -> Result<(), String> {
+    if !(1..=500).contains(&limit_mb) {
+        return Err("Attachment size limit must be between 1 and 500 MB".to_string());
+    }
+    let mut workspaces = state.workspaces.lock().map_err(|e| e.to_string())?;
+    let ws = workspaces
+        .get_mut(window.label())
+        .ok_or_else(|| "No workspace open".to_string())?;
+    ws.set_attachment_max_size_bytes(Some(limit_mb * 1024 * 1024))
+        .map_err(|e| e.to_string())
+}
diff --git a/krillnotes-desktop/src-tauri/src/lib.rs b/krillnotes-desktop/src-tauri/src/lib.rs
index de79fea1..7d0b7032 100644
--- a/krillnotes-desktop/src-tauri/src/lib.rs
+++ b/krillnotes-desktop/src-tauri/src/lib.rs
@@ -477,6 +477,8 @@ pub fn run() {
             delete_attachment,
             restore_attachment,
             open_attachment,
+            get_attachment_max_size_mb,
+            set_attachment_max_size_mb,
             undo,
             redo,
             can_undo,
diff --git a/krillnotes-desktop/src/components/WorkspacePropertiesDialog.tsx b/krillnotes-desktop/src/components/WorkspacePropertiesDialog.tsx
index 17e6a583..3dee6ee1 100644
--- a/krillnotes-desktop/src/components/WorkspacePropertiesDialog.tsx
+++ b/krillnotes-desktop/src/components/WorkspacePropertiesDialog.tsx
@@ -51,10 +51,12 @@ function WorkspacePropertiesDialog({ isOpen, onClose }: WorkspacePropertiesDialo
   const [error, setError] = useState('');
   const [saving, setSaving] = useState(false);
   const [isOwner, setIsOwner] = useState(true);
+  const [attachmentSizeMb, setAttachmentSizeMb] = useState<number>(10);
 
   useEffect(() => {
     if (!isOpen) return;
     invoke<boolean>('is_workspace_owner').then(setIsOwner).catch(() => setIsOwner(false));
+    invoke<number>('get_attachment_max_size_mb').then(setAttachmentSizeMb).catch(() => {});
     invoke<WorkspaceMetadata>('get_workspace_metadata')
       .then(meta => {
         setAuthorName(meta.authorName ?? '');
@@ -120,6 +122,7 @@ function WorkspacePropertiesDialog({ isOpen, onClose }: WorkspacePropertiesDialo
         tags: parseTags(tagsRaw),
       };
       await invoke('set_workspace_metadata', { metadata });
+      await invoke('set_attachment_max_size_mb', { limitMb: attachmentSizeMb });
       onClose();
     } catch (err) {
       setError(t('workspace.propertiesSaveFailed', { error: String(err) }));
@@ -151,6 +154,50 @@ function WorkspacePropertiesDialog({ isOpen, onClose }: WorkspacePropertiesDialo
           </div>
         )}
 
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide mb-3">
+          {t('workspace.settingsSection')}
+        </h3>
+
+        <div className="mb-3">
+          <label className="block text-sm font-medium mb-1">
+            {t('workspace.attachmentSizeLimit')}
+          </label>
+          <div className="flex items-center gap-2">
+            <input
+              type="number"
+              inputMode="numeric"
+              min={1}
+              max={500}
+              step={1}
+              value={attachmentSizeMb}
+              onChange={e => {
+                const v = parseInt(e.target.value, 10);
+                if (!isNaN(v)) setAttachmentSizeMb(v);
+              }}
+              className={`w-24 bg-secondary border border-secondary rounded px-3 py-1.5 text-sm ${!isOwner ? 'opacity-60 cursor-default' : ''}`}
+              readOnly={!isOwner}
+              disabled={!isOwner}
+            />
+            <span className="text-sm text-muted-foreground">
+              {t('workspace.attachmentSizeLimitUnit')}
+            </span>
+          </div>
+          <p className="text-xs text-muted-foreground mt-1">
+            {t('workspace.attachmentSizeLimitHelper')}
+          </p>
+          {(attachmentSizeMb < 1 || attachmentSizeMb > 500) && (
+            <p className="text-xs text-red-500 mt-1">
+              {t('workspace.attachmentSizeLimitError')}
+            </p>
+          )}
+        </div>
+
+        <hr className="border-secondary my-4" />
+
+        <h3 className="text-sm font-semibold text-muted-foreground uppercase tracking-wide mb-3">
+          {t('workspace.propertiesSection')}
+        </h3>
+
         {field(t('workspace.authorName'), (
           <input type="text" value={authorName} onChange={e => setAuthorName(e.target.value)}
             className={inputClass} placeholder={t('workspace.authorNamePlaceholder')}
@@ -247,7 +294,7 @@ function WorkspacePropertiesDialog({ isOpen, onClose }: WorkspacePropertiesDialo
               </button>
               <button onClick={handleSave}
                 className="px-4 py-2 bg-primary text-primary-foreground rounded hover:bg-primary/90"
-                disabled={saving}>
+                disabled={saving || attachmentSizeMb < 1 || attachmentSizeMb > 500}>
                 {saving ? t('common.saving') : t('common.save')}
               </button>
             </>
diff --git a/krillnotes-desktop/src/i18n/locales/de.json b/krillnotes-desktop/src/i18n/locales/de.json
index c12b9f64..91ef3af5 100644
--- a/krillnotes-desktop/src/i18n/locales/de.json
+++ b/krillnotes-desktop/src/i18n/locales/de.json
@@ -165,7 +165,13 @@
     "redoTooltip": "Wiederholen (Cmd+Umschalt+Z)",
     "schemaMigrated_one": "Schema \"{{schemaName}}\" aktualisiert — {{count}} Notiz auf Version {{version}} migriert",
     "schemaMigrated_other": "Schema \"{{schemaName}}\" aktualisiert — {{count}} Notizen auf Version {{version}} migriert",
-    "propertiesReadOnly": "Nur der Eigentümer des Arbeitsbereichs kann diese Eigenschaften ändern."
+    "propertiesReadOnly": "Nur der Eigentümer des Arbeitsbereichs kann diese Eigenschaften ändern.",
+    "settingsSection": "Einstellungen",
+    "propertiesSection": "Eigenschaften",
+    "attachmentSizeLimit": "Maximale Anhangsgröße",
+    "attachmentSizeLimitHelper": "Maximale Dateigröße für Anhänge in diesem Arbeitsbereich",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "Muss zwischen 1 und 500 MB liegen"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/en.json b/krillnotes-desktop/src/i18n/locales/en.json
index 5c60a660..6873b007 100644
--- a/krillnotes-desktop/src/i18n/locales/en.json
+++ b/krillnotes-desktop/src/i18n/locales/en.json
@@ -165,7 +165,13 @@
     "redoTooltip": "Redo (Cmd+Shift+Z)",
     "schemaMigrated_one": "\"{{schemaName}}\" schema updated — {{count}} note migrated to version {{version}}",
     "schemaMigrated_other": "\"{{schemaName}}\" schema updated — {{count}} notes migrated to version {{version}}",
-    "propertiesReadOnly": "Only the workspace owner can modify these properties."
+    "propertiesReadOnly": "Only the workspace owner can modify these properties.",
+    "settingsSection": "Settings",
+    "propertiesSection": "Properties",
+    "attachmentSizeLimit": "Maximum attachment size",
+    "attachmentSizeLimitHelper": "Maximum file size for attachments in this workspace",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "Must be between 1 and 500 MB"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/es.json b/krillnotes-desktop/src/i18n/locales/es.json
index 67fedec6..69a5d706 100644
--- a/krillnotes-desktop/src/i18n/locales/es.json
+++ b/krillnotes-desktop/src/i18n/locales/es.json
@@ -165,7 +165,13 @@
     "redoTooltip": "Rehacer (Cmd+Mayús+Z)",
     "schemaMigrated_one": "Esquema \"{{schemaName}}\" actualizado — {{count}} nota migrada a versión {{version}}",
     "schemaMigrated_other": "Esquema \"{{schemaName}}\" actualizado — {{count}} notas migradas a versión {{version}}",
-    "propertiesReadOnly": "Solo el propietario del espacio de trabajo puede modificar estas propiedades."
+    "propertiesReadOnly": "Solo el propietario del espacio de trabajo puede modificar estas propiedades.",
+    "settingsSection": "Configuración",
+    "propertiesSection": "Propiedades",
+    "attachmentSizeLimit": "Tamaño máximo de adjuntos",
+    "attachmentSizeLimitHelper": "Tamaño máximo de archivo para adjuntos en este espacio de trabajo",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "Debe estar entre 1 y 500 MB"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/fr.json b/krillnotes-desktop/src/i18n/locales/fr.json
index 5f271e69..96fa8343 100644
--- a/krillnotes-desktop/src/i18n/locales/fr.json
+++ b/krillnotes-desktop/src/i18n/locales/fr.json
@@ -165,7 +165,13 @@
     "redoTooltip": "Rétablir (Cmd+Maj+Z)",
     "schemaMigrated_one": "Schéma \"{{schemaName}}\" mis à jour — {{count}} note migrée vers la version {{version}}",
     "schemaMigrated_other": "Schéma \"{{schemaName}}\" mis à jour — {{count}} notes migrées vers la version {{version}}",
-    "propertiesReadOnly": "Seul le propriétaire de l'espace de travail peut modifier ces propriétés."
+    "propertiesReadOnly": "Seul le propriétaire de l'espace de travail peut modifier ces propriétés.",
+    "settingsSection": "Paramètres",
+    "propertiesSection": "Propriétés",
+    "attachmentSizeLimit": "Taille maximale des pièces jointes",
+    "attachmentSizeLimitHelper": "Taille maximale des fichiers joints dans cet espace de travail",
+    "attachmentSizeLimitUnit": "Mo",
+    "attachmentSizeLimitError": "Doit être compris entre 1 et 500 Mo"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/ja.json b/krillnotes-desktop/src/i18n/locales/ja.json
index 10f39d95..09fa5446 100644
--- a/krillnotes-desktop/src/i18n/locales/ja.json
+++ b/krillnotes-desktop/src/i18n/locales/ja.json
@@ -165,7 +165,13 @@
     "redoTooltip": "やり直す (Cmd+Shift+Z)",
     "schemaMigrated_one": "スキーマ「{{schemaName}}」更新 — {{count}}件のノートをバージョン{{version}}に移行しました",
     "schemaMigrated_other": "スキーマ「{{schemaName}}」更新 — {{count}}件のノートをバージョン{{version}}に移行しました",
-    "propertiesReadOnly": "ワークスペースのプロパティを変更できるのはオーナーのみです。"
+    "propertiesReadOnly": "ワークスペースのプロパティを変更できるのはオーナーのみです。",
+    "settingsSection": "設定",
+    "propertiesSection": "プロパティ",
+    "attachmentSizeLimit": "添付ファイルの最大サイズ",
+    "attachmentSizeLimitHelper": "このワークスペースの添付ファイルの最大サイズ",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "1〜500 MBの範囲で指定してください"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/ko.json b/krillnotes-desktop/src/i18n/locales/ko.json
index 709cb2c5..59c71fe2 100644
--- a/krillnotes-desktop/src/i18n/locales/ko.json
+++ b/krillnotes-desktop/src/i18n/locales/ko.json
@@ -165,7 +165,13 @@
     "redoTooltip": "다시 실행 (Cmd+Shift+Z)",
     "schemaMigrated_one": "스키마 \"{{schemaName}}\" 업데이트 — {{count}}개의 노트가 버전 {{version}}으로 마이그레이션됨",
     "schemaMigrated_other": "스키마 \"{{schemaName}}\" 업데이트 — {{count}}개의 노트가 버전 {{version}}으로 마이그레이션됨",
-    "propertiesReadOnly": "워크스페이스 소유자만 이 속성을 수정할 수 있습니다."
+    "propertiesReadOnly": "워크스페이스 소유자만 이 속성을 수정할 수 있습니다.",
+    "settingsSection": "설정",
+    "propertiesSection": "속성",
+    "attachmentSizeLimit": "최대 첨부 파일 크기",
+    "attachmentSizeLimitHelper": "이 워크스페이스의 첨부 파일 최대 크기",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "1~500 MB 사이여야 합니다"
   },
   "dialogs": {
     "password": {
diff --git a/krillnotes-desktop/src/i18n/locales/zh.json b/krillnotes-desktop/src/i18n/locales/zh.json
index eea0bd5a..ccc39898 100644
--- a/krillnotes-desktop/src/i18n/locales/zh.json
+++ b/krillnotes-desktop/src/i18n/locales/zh.json
@@ -165,7 +165,13 @@
     "redoTooltip": "重做 (Cmd+Shift+Z)",
     "schemaMigrated_one": "模式 \"{{schemaName}}\" 已更新 — {{count}} 个笔记已迁移到版本 {{version}}",
     "schemaMigrated_other": "模式 \"{{schemaName}}\" 已更新 — {{count}} 个笔记已迁移到版本 {{version}}",
-    "propertiesReadOnly": "只有工作区所有者才能修改这些属性。"
+    "propertiesReadOnly": "只有工作区所有者才能修改这些属性。",
+    "settingsSection": "设置",
+    "propertiesSection": "属性",
+    "attachmentSizeLimit": "附件最大大小",
+    "attachmentSizeLimitHelper": "此工作区附件的最大文件大小",
+    "attachmentSizeLimitUnit": "MB",
+    "attachmentSizeLimitError": "必须在 1 到 500 MB 之间"
   },
   "dialogs": {
     "password": {