--- a/devtools/client/storage.ftl
+++ b/devtools/client/storage.ftl
@@ -74,16 +74,24 @@ storage-table-headers-cache-status = 状态
 storage-tree-labels-cookies = Cookie
 storage-tree-labels-local-storage = 本地存储
 storage-tree-labels-session-storage = 会话存储
 storage-tree-labels-indexed-db = Indexed DB
 storage-tree-labels-cache = 缓存存储
 
 ##
 
+# Tooltip for the button that collapses the right panel in the
+# storage UI when the panel is closed.
+storage-expand-pane =
+    .title = 展开窗格
+# Tooltip for the button that collapses the right panel in the
+# storage UI when the panel is open.
+storage-collapse-pane =
+    .title = 折叠窗格
 # String displayed in the expires column when the cookie is a Session Cookie
 storage-expires-session = 会话
 # Heading displayed over the item value in the sidebar
 storage-data = 数据
 # Heading displayed over the item parsed value in the sidebar
 storage-parsed-value = 解析的值
 # Warning notification when IndexedDB database could not be deleted immediately.
 # Variables: