diff --git a/src/components/layout/AppSidebar.vue b/src/components/layout/AppSidebar.vue
index 8383f83754..0cbff9faa8 100644
--- a/src/components/layout/AppSidebar.vue
+++ b/src/components/layout/AppSidebar.vue
@@ -85,7 +85,7 @@ async function refreshTree() {
           <TooltipContent>{{ t("sidebar.export") }}</TooltipContent>
         </Tooltip>
       </div>
-      <div class="flex-1 overflow-y-auto">
+      <div class="flex-1 min-h-0">
         <ConnectionTree />
       </div>
     </div>
diff --git a/src/components/sidebar/ConnectionTree.vue b/src/components/sidebar/ConnectionTree.vue
index 7dc5d5fb3d..350f1d5399 100644
--- a/src/components/sidebar/ConnectionTree.vue
+++ b/src/components/sidebar/ConnectionTree.vue
@@ -5,8 +5,11 @@ import { Search, X, ListFilter, Check, FolderPlus } from "lucide-vue-next";
 import { useConnectionStore } from "@/stores/connectionStore";
 import type { TreeNode } from "@/types/database";
 import { matchSidebarLabel } from "@/lib/sidebarSearch";
+import { flattenTree, shouldVirtualizeFlatTree, type FlatTreeNode } from "@/composables/useFlatTree";
 import TreeItem from "./TreeItem.vue";
 import DatabaseIcon from "@/components/icons/DatabaseIcon.vue";
+import { RecycleScroller } from "vue-virtual-scroller";
+import "vue-virtual-scroller/dist/vue-virtual-scroller.css";
 import {
   DropdownMenu,
   DropdownMenuTrigger,
@@ -145,22 +148,8 @@ const filteredNodes = computed(() => {
   return nodes;
 });
 
-const TOP_LEVEL_PAGE_SIZE = 50;
-const topLevelDisplayLimit = ref(TOP_LEVEL_PAGE_SIZE);
-
-const visibleFilteredNodes = computed(() => filteredNodes.value.slice(0, topLevelDisplayLimit.value));
-
-const hasMoreTopLevel = computed(() => filteredNodes.value.length > topLevelDisplayLimit.value);
-
-const remainingTopLevelCount = computed(() => filteredNodes.value.length - topLevelDisplayLimit.value);
-
-function showMoreTopLevel() {
-  topLevelDisplayLimit.value += TOP_LEVEL_PAGE_SIZE;
-}
-
-watch(filteredNodes, () => {
-  topLevelDisplayLimit.value = TOP_LEVEL_PAGE_SIZE;
-});
+const flatNodes = computed<FlatTreeNode[]>(() => flattenTree(filteredNodes.value));
+const useVirtualTree = computed(() => shouldVirtualizeFlatTree(flatNodes.value.length));
 
 const pendingRenameGroupId = ref<string | null>(null);
 
@@ -179,7 +168,7 @@ function onSearchToggle(node: TreeNode) {
 </script>
 
 <template>
-  <div class="text-sm select-none">
+  <div class="h-full min-h-0 flex flex-col text-sm select-none">
     <div v-if="store.treeNodes.length > 0" class="sticky top-0 z-10 bg-background px-2 py-1">
       <div class="relative flex items-center gap-1">
         <div class="relative flex-1">
@@ -243,23 +232,37 @@ function onSearchToggle(node: TreeNode) {
         </DropdownMenu>
       </div>
     </div>
-    <TreeItem
-      v-for="node in visibleFilteredNodes"
-      :key="node.id"
-      :node="node"
-      :depth="0"
-      :drag-disabled="isFiltering"
-      :pending-rename="pendingRenameGroupId === node.id"
-      @search-toggle="onSearchToggle"
-      @rename-started="pendingRenameGroupId = null"
-    />
-    <div
-      v-if="hasMoreTopLevel"
-      class="flex items-center gap-1.5 py-1 px-2 cursor-pointer hover:bg-accent text-xs text-muted-foreground"
-      style="padding-left: 8px"
-      @click="showMoreTopLevel"
+    <RecycleScroller
+      v-if="flatNodes.length > 0 && useVirtualTree"
+      class="min-h-0 flex-1 overflow-y-auto"
+      :items="flatNodes"
+      :item-size="28"
+      key-field="id"
+      type-field="type"
+      flow-mode
     >
-      <span>{{ t("sidebar.showMore", { count: Math.min(TOP_LEVEL_PAGE_SIZE, remainingTopLevelCount) }) }}</span>
+      <template #default="{ item }">
+        <TreeItem
+          :node="item.node"
+          :depth="item.depth"
+          :drag-disabled="isFiltering"
+          :pending-rename="pendingRenameGroupId === item.node.id"
+          @search-toggle="onSearchToggle"
+          @rename-started="pendingRenameGroupId = null"
+        />
+      </template>
+    </RecycleScroller>
+    <div v-else-if="flatNodes.length > 0" class="min-h-0 flex-1 overflow-y-auto">
+      <TreeItem
+        v-for="item in flatNodes"
+        :key="item.id"
+        :node="item.node"
+        :depth="item.depth"
+        :drag-disabled="isFiltering"
+        :pending-rename="pendingRenameGroupId === item.node.id"
+        @search-toggle="onSearchToggle"
+        @rename-started="pendingRenameGroupId = null"
+      />
     </div>
     <div v-if="store.treeNodes.length === 0" class="px-3 py-8 text-center text-muted-foreground text-xs">
       {{ t("sidebar.noConnections") }}
diff --git a/src/components/sidebar/TreeItem.vue b/src/components/sidebar/TreeItem.vue
index 5b7a8d123f..94c86f706f 100644
--- a/src/components/sidebar/TreeItem.vue
+++ b/src/components/sidebar/TreeItem.vue
@@ -58,6 +58,7 @@ import type { DatabaseType, QueryResult, TreeNode, TreeNodeType } from "@/types/
 import * as api from "@/lib/api";
 import { uuid } from "@/lib/utils";
 import { resolveDefaultDatabase } from "@/lib/defaultDatabase";
+import { canTreeNodeShowExpander, treeItemPaddingLeft } from "@/lib/sidebarTreeItemLayout";
 import {
   DATABASE_EXPORT_PAGE_SIZE,
   DATABASE_EXPORT_ROW_LIMIT,
@@ -173,7 +174,7 @@ function getIconInfo(node: TreeNode): { icon: any; colorClass: string } | null {
     case "redis-db":
       return { icon: Database, colorClass: "text-red-400" };
     case "mongo-db":
-      return { icon: Database, colorClass: "text-green-500" };
+      return { icon: Database, colorClass: "text-yellow-500" };
     case "mongo-collection":
       return { icon: Table, colorClass: "text-green-400" };
     default:
@@ -181,16 +182,6 @@ function getIconInfo(node: TreeNode): { icon: any; colorClass: string } | null {
   }
 }
 
-const leafTypes: Set<TreeNodeType> = new Set([
-  "column",
-  "index",
-  "fkey",
-  "trigger",
-  "object-browser",
-  "redis-db",
-  "mongo-collection",
-  "saved-sql-file",
-]);
 const groupTypes: Set<TreeNodeType> = new Set([
   "group-columns",
   "group-indexes",
@@ -291,8 +282,8 @@ async function toggle() {
 function onClick() {
   const node = props.node;
   if (canOpenObjectBrowser.value) {
-    const shouldOpenObjectBrowser = !canExpand || !node.isExpanded;
-    if (canExpand) void toggle();
+    const shouldOpenObjectBrowser = !canExpand.value || !node.isExpanded;
+    if (canExpand.value) void toggle();
     if (shouldOpenObjectBrowser) void openObjectBrowser();
     return;
   }
@@ -300,7 +291,7 @@ function onClick() {
     void openObjectBrowser();
     return;
   }
-  const action = treeNodeRowAction(node.type, canExpand);
+  const action = treeNodeRowAction(node.type, canExpand.value);
   if (action === "open-data") {
     openData();
   } else if (node.type === "saved-sql-file") {
@@ -1087,7 +1078,12 @@ function openFieldLineage() {
   };
 }
 
-const canExpand = !leafTypes.has(props.node.type);
+const canExpand = computed(() =>
+  canTreeNodeShowExpander({
+    type: props.node.type,
+    childCount: props.node.children?.length ?? 0,
+  }),
+);
 const nodeConfig = computed(() =>
   props.node.connectionId ? connectionStore.getConfig(props.node.connectionId) : undefined,
 );
@@ -1163,7 +1159,7 @@ const columnComment = computed(() =>
     ? (props.node.meta as any).comment
     : null,
 );
-const paddingLeft = `${props.depth * 16 + 8}px`;
+const paddingLeft = computed(() => treeItemPaddingLeft(props.depth));
 const isConnected = computed(
   () =>
     props.node.type === "connection" &&
@@ -1186,40 +1182,15 @@ const isActiveConnectionScope = computed(
 const rowStyle = computed(() => {
   const color = connectionColor.value;
   return {
-    paddingLeft,
+    paddingLeft: paddingLeft.value,
     backgroundColor: hexToRgba(color, isActiveConnectionScope.value ? 0.14 : 0.08),
   };
 });
 
-const CHILDREN_PAGE_SIZE = 50;
-const displayLimit = ref(CHILDREN_PAGE_SIZE);
-
-const visibleChildren = computed(() => {
-  if (!props.node.children) return [];
-  return props.node.children.slice(0, displayLimit.value);
-});
-
-const hasMoreChildren = computed(() => (props.node.children?.length ?? 0) > displayLimit.value);
-
-const remainingCount = computed(() => (props.node.children?.length ?? 0) - displayLimit.value);
-
 function togglePin() {
   connectionStore.toggleTreeNodePin(props.node.id);
 }
 
-watch(
-  () => props.node.isExpanded,
-  (expanded) => {
-    if (!expanded) displayLimit.value = CHILDREN_PAGE_SIZE;
-  },
-);
-
-async function showMore() {
-  if ((props.node.children?.length ?? 0) > displayLimit.value) {
-    displayLimit.value += CHILDREN_PAGE_SIZE;
-  }
-}
-
 // --- Connection Group Management ---
 const isRenamingGroup = ref(false);
 const renameInput = ref("");
@@ -1484,25 +1455,6 @@ const isDragging = computed(() => dragState.active && dragState.draggedId === pr
             <Pin class="w-3 h-3" :class="{ 'fill-current': isPinned }" />
           </button>
         </div>
-        <template v-if="node.isExpanded && node.children">
-          <TreeItem
-            v-for="child in visibleChildren"
-            :key="child.id"
-            :node="child"
-            :depth="depth + 1"
-            :drag-disabled="dragDisabled"
-            @search-toggle="emit('search-toggle', $event)"
-          />
-          <div
-            v-if="hasMoreChildren"
-            class="flex items-center gap-1.5 py-1 px-2 cursor-pointer hover:bg-accent text-xs text-muted-foreground"
-            :style="{ paddingLeft: `${(depth + 1) * 16 + 8}px` }"
-            @click="showMore"
-          >
-            <Loader2 v-if="node.isLoading" class="w-3 h-3 shrink-0 animate-spin" />
-            <span>{{ t("sidebar.showMore", { count: Math.min(CHILDREN_PAGE_SIZE, remainingCount) }) }}</span>
-          </div>
-        </template>
       </div>
     </ContextMenuTrigger>
 
diff --git a/src/composables/useFlatTree.ts b/src/composables/useFlatTree.ts
new file mode 100644
index 0000000000..d759bd9cea
--- /dev/null
+++ b/src/composables/useFlatTree.ts
@@ -0,0 +1,27 @@
+import type { TreeNode, TreeNodeType } from "@/types/database";
+
+export interface FlatTreeNode {
+  node: TreeNode;
+  depth: number;
+  id: string;
+  type: TreeNodeType;
+}
+
+function walk(children: TreeNode[], depth: number, result: FlatTreeNode[]) {
+  for (const node of children) {
+    result.push({ node, depth, id: node.id, type: node.type });
+    if (node.isExpanded && node.children) {
+      walk(node.children, depth + 1, result);
+    }
+  }
+}
+
+export function flattenTree(nodes: TreeNode[]): FlatTreeNode[] {
+  const result: FlatTreeNode[] = [];
+  walk(nodes, 0, result);
+  return result;
+}
+
+export function shouldVirtualizeFlatTree(count: number): boolean {
+  return count >= 400;
+}
diff --git a/src/lib/sidebarTreeItemLayout.ts b/src/lib/sidebarTreeItemLayout.ts
new file mode 100644
index 0000000000..c23d08f52b
--- /dev/null
+++ b/src/lib/sidebarTreeItemLayout.ts
@@ -0,0 +1,28 @@
+import type { TreeNodeType } from "@/types/database";
+
+const leafTypes: Set<TreeNodeType> = new Set([
+  "column",
+  "index",
+  "fkey",
+  "trigger",
+  "object-browser",
+  "redis-db",
+  "mongo-collection",
+  "saved-sql-file",
+]);
+
+export function treeItemPaddingLeft(depth: number): string {
+  return `${depth * 16 + 8}px`;
+}
+
+export function canTreeNodeExpand(type: TreeNodeType): boolean {
+  return !leafTypes.has(type);
+}
+
+export function canTreeNodeShowExpander({ type, childCount }: { type: TreeNodeType; childCount?: number }): boolean {
+  if (!canTreeNodeExpand(type)) return false;
+  if (type === "saved-sql-root" || type === "saved-sql-folder") {
+    return (childCount ?? 0) > 0;
+  }
+  return true;
+}
diff --git a/tests/sidebarTreeItemLayout.test.ts b/tests/sidebarTreeItemLayout.test.ts
new file mode 100644
index 0000000000..17fad700aa
--- /dev/null
+++ b/tests/sidebarTreeItemLayout.test.ts
@@ -0,0 +1,33 @@
+import { strict as assert } from "node:assert";
+import test from "node:test";
+import { canTreeNodeExpand, canTreeNodeShowExpander, treeItemPaddingLeft } from "../src/lib/sidebarTreeItemLayout.ts";
+
+test("treeItemPaddingLeft converts tree depth to sidebar indentation", () => {
+  assert.equal(treeItemPaddingLeft(0), "8px");
+  assert.equal(treeItemPaddingLeft(1), "24px");
+  assert.equal(treeItemPaddingLeft(2), "40px");
+});
+
+test("canTreeNodeExpand only returns true for expandable sidebar node types", () => {
+  assert.equal(canTreeNodeExpand("connection"), true);
+  assert.equal(canTreeNodeExpand("database"), true);
+  assert.equal(canTreeNodeExpand("schema"), true);
+  assert.equal(canTreeNodeExpand("table"), true);
+  assert.equal(canTreeNodeExpand("view"), true);
+  assert.equal(canTreeNodeExpand("saved-sql-root"), true);
+  assert.equal(canTreeNodeExpand("saved-sql-folder"), true);
+
+  assert.equal(canTreeNodeExpand("saved-sql-file"), false);
+  assert.equal(canTreeNodeExpand("object-browser"), false);
+  assert.equal(canTreeNodeExpand("column"), false);
+  assert.equal(canTreeNodeExpand("index"), false);
+  assert.equal(canTreeNodeExpand("redis-db"), false);
+  assert.equal(canTreeNodeExpand("mongo-collection"), false);
+});
+
+test("canTreeNodeShowExpander hides empty saved SQL containers", () => {
+  assert.equal(canTreeNodeShowExpander({ type: "saved-sql-root", childCount: 0 }), false);
+  assert.equal(canTreeNodeShowExpander({ type: "saved-sql-folder", childCount: 0 }), false);
+  assert.equal(canTreeNodeShowExpander({ type: "saved-sql-root", childCount: 1 }), true);
+  assert.equal(canTreeNodeShowExpander({ type: "saved-sql-folder", childCount: 1 }), true);
+});
diff --git a/tests/useFlatTree.test.ts b/tests/useFlatTree.test.ts
new file mode 100644
index 0000000000..69a98f7bc6
--- /dev/null
+++ b/tests/useFlatTree.test.ts
@@ -0,0 +1,42 @@
+import { strict as assert } from "node:assert";
+import test from "node:test";
+import { flattenTree, shouldVirtualizeFlatTree } from "../src/composables/useFlatTree.ts";
+import type { TreeNode } from "../src/types/database.ts";
+
+test("flattenTree preserves depth and node type for virtualized sidebar rows", () => {
+  const nodes: TreeNode[] = [
+    {
+      id: "conn",
+      label: "Connection",
+      type: "connection",
+      isExpanded: true,
+      children: [
+        { id: "conn:file", label: "Query.sql", type: "saved-sql-file" },
+        {
+          id: "conn:db",
+          label: "db",
+          type: "database",
+          isExpanded: true,
+          children: [{ id: "conn:db:table", label: "table", type: "table" }],
+        },
+      ],
+    },
+  ];
+
+  const flat = flattenTree(nodes);
+
+  assert.deepEqual(
+    flat.map((item) => ({ id: item.id, depth: item.depth, type: item.type })),
+    [
+      { id: "conn", depth: 0, type: "connection" },
+      { id: "conn:file", depth: 1, type: "saved-sql-file" },
+      { id: "conn:db", depth: 1, type: "database" },
+      { id: "conn:db:table", depth: 2, type: "table" },
+    ],
+  );
+});
+
+test("shouldVirtualizeFlatTree only virtualizes very large sidebar trees", () => {
+  assert.equal(shouldVirtualizeFlatTree(399), false);
+  assert.equal(shouldVirtualizeFlatTree(400), true);
+});