diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 7f4f5a7e..1760cfd4 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -1,12 +1,12 @@
 {
     "name": "fileglancer",
-    "version": "3.3.0",
+    "version": "3.4.0-a0",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "fileglancer",
-            "version": "3.3.0",
+            "version": "3.4.0-a0",
             "license": "BSD-3-Clause",
             "dependencies": {
                 "@bioimagetools/capability-manifest": "0.7.1",
diff --git a/frontend/package.json b/frontend/package.json
index 384f16f6..69819852 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
 {
     "name": "fileglancer",
     "type": "module",
-    "version": "3.3.0",
+    "version": "3.4.0-a0",
     "description": "Browse, share, and publish files on the Janelia file system",
     "keywords": [
         "ngff",
diff --git a/frontend/src/__tests__/componentTests/NeuroglancerView.test.tsx b/frontend/src/__tests__/componentTests/NeuroglancerView.test.tsx
index 23990f83..c24423ab 100644
--- a/frontend/src/__tests__/componentTests/NeuroglancerView.test.tsx
+++ b/frontend/src/__tests__/componentTests/NeuroglancerView.test.tsx
@@ -90,8 +90,10 @@ vi.mock('@/components/ui/Views/ViewBrokenBanner', () => ({
 vi.mock('@/components/ui/Views/ViewerSidebar', () => ({
   default: ({
     bridge,
-    editState
+    editState,
+    tab
   }: {
+    tab: string;
     bridge: { setState: (s: Record<string, unknown>) => void };
     editState: {
       markEdited: () => void;
@@ -99,7 +101,7 @@ vi.mock('@/components/ui/Views/ViewerSidebar', () => ({
       removeSource: (key: string) => void;
     };
   }) => (
-    <aside aria-label="View data sidebar">
+    <aside aria-label="View data sidebar" data-tab={tab}>
       <button onClick={() => editState.addSources(['plainKey'])} type="button">
         fake add unsupported
       </button>
@@ -650,6 +652,25 @@ describe('NeuroglancerView', () => {
     expect(screen.queryByRole('complementary')).toBeNull();
   });
 
+  it('opens the sidebar to the Sources tab from the info button', async () => {
+    useViewsQuery.mockReturnValue({ data: [OWNED] });
+    renderViewer();
+    const sources = screen.getByRole('button', {
+      name: 'View and edit data sources'
+    });
+    await userEvent.click(sources);
+    expect(
+      screen.getByRole('complementary', { name: 'View data sidebar' })
+    ).toHaveAttribute('data-tab', 'sources');
+    expect(sources).toHaveAttribute('aria-pressed', 'true');
+    expect(screen.getByRole('button', { name: 'Add data' })).toHaveAttribute(
+      'aria-pressed',
+      'false'
+    );
+    await userEvent.click(sources);
+    expect(screen.queryByRole('complementary')).toBeNull();
+  });
+
   it('toggling the sidebar keeps the same iframe', async () => {
     useViewsQuery.mockReturnValue({ data: [OWNED] });
     renderViewer();
diff --git a/frontend/src/__tests__/componentTests/ViewerSidebar.test.tsx b/frontend/src/__tests__/componentTests/ViewerSidebar.test.tsx
index fa5013b7..ed648bc2 100644
--- a/frontend/src/__tests__/componentTests/ViewerSidebar.test.tsx
+++ b/frontend/src/__tests__/componentTests/ViewerSidebar.test.tsx
@@ -99,6 +99,8 @@ function setup() {
       bridge={fake.bridge}
       editState={editState}
       onClose={vi.fn()}
+      onTabChange={vi.fn()}
+      tab="sources"
       viewLayers={VIEW_LAYERS}
     />
   );
diff --git a/frontend/src/components/NeuroglancerView.tsx b/frontend/src/components/NeuroglancerView.tsx
index cabf0c7d..ebcf7d81 100644
--- a/frontend/src/components/NeuroglancerView.tsx
+++ b/frontend/src/components/NeuroglancerView.tsx
@@ -10,6 +10,7 @@ import {
   HiOutlineDownload,
   HiOutlineExternalLink,
   HiOutlineArrowsExpand,
+  HiOutlineInformationCircle,
   HiOutlinePlusCircle
 } from 'react-icons/hi';
 
@@ -37,6 +38,7 @@ import type { RelinkTarget } from '@/components/ui/Dialogs/RelinkDialog';
 import ViewBrokenBanner from '@/components/ui/Views/ViewBrokenBanner';
 import ViewSaveControls from '@/components/ui/Views/ViewSaveControls';
 import ViewerSidebar from '@/components/ui/Views/ViewerSidebar';
+import type { SidebarTab } from '@/components/ui/Views/ViewerSidebar';
 
 type ToolbarIconButtonProps = {
   readonly label: string;
@@ -109,7 +111,10 @@ export default function NeuroglancerView() {
   // Wait out the mount refetch: a cached state can predate a Save made just
   // before leaving this page.
   const [iframeSrc, setIframeSrc] = useState<string | null>(null);
-  const [sidebarOpen, setSidebarOpen] = useState(false);
+  // null when the sidebar is closed.
+  const [sidebarTab, setSidebarTab] = useState<SidebarTab | null>(null);
+  const toggleSidebar = (tab: SidebarTab) =>
+    setSidebarTab(current => (current === tab ? null : tab));
   // While resizing, the overlay covers the iframe: over the iframe, the
   // pointer's moves go to Neuroglancer and the drag stalls.
   const [resizing, setResizing] = useState(false);
@@ -335,8 +340,16 @@ export default function NeuroglancerView() {
               <ToolbarIconButton
                 icon={HiOutlinePlusCircle}
                 label="Add data"
-                onClick={() => setSidebarOpen(open => !open)}
-                pressed={sidebarOpen}
+                onClick={() => toggleSidebar('add')}
+                pressed={sidebarTab === 'add'}
+              />
+            ) : null}
+            {canAddData ? (
+              <ToolbarIconButton
+                icon={HiOutlineInformationCircle}
+                label="View and edit data sources"
+                onClick={() => toggleSidebar('sources')}
+                pressed={sidebarTab === 'sources'}
               />
             ) : null}
             <ToolbarIconButton
@@ -396,7 +409,7 @@ export default function NeuroglancerView() {
           src={iframeSrc ?? externalUrl}
           title="Neuroglancer viewer"
         />
-        {canAddData && sidebarOpen ? (
+        {canAddData && sidebarTab ? (
           <div
             className={`absolute inset-0 ${resizing ? 'cursor-col-resize' : 'pointer-events-none'}`}
           >
@@ -421,7 +434,9 @@ export default function NeuroglancerView() {
                 <ViewerSidebar
                   bridge={bridge}
                   editState={editState}
-                  onClose={() => setSidebarOpen(false)}
+                  onClose={() => setSidebarTab(null)}
+                  onTabChange={setSidebarTab}
+                  tab={sidebarTab}
                   viewLayers={ownedView?.layers ?? []}
                 />
               </Panel>
diff --git a/frontend/src/components/ui/Views/ViewerSidebar.tsx b/frontend/src/components/ui/Views/ViewerSidebar.tsx
index 25edbd58..58b70fcb 100644
--- a/frontend/src/components/ui/Views/ViewerSidebar.tsx
+++ b/frontend/src/components/ui/Views/ViewerSidebar.tsx
@@ -14,12 +14,16 @@ import type { ViewEditState } from '@/hooks/useViewEditState';
 import type { ViewLayer } from '@/queries/viewQueries';
 import type { NgState } from '@/utils/viewCheckout';
 
+export type SidebarTab = 'add' | 'sources';
+
 type ViewerSidebarProps = {
   readonly bridge: NeuroglancerBridge;
   /** The View's saved layer rows. */
   readonly viewLayers: ViewLayer[];
   readonly editState: ViewEditState;
   readonly onClose: () => void;
+  readonly tab: SidebarTab;
+  readonly onTabChange: (tab: SidebarTab) => void;
 };
 
 /**
@@ -31,7 +35,9 @@ export default function ViewerSidebar({
   bridge,
   viewLayers,
   editState,
-  onClose
+  onClose,
+  tab,
+  onTabChange
 }: ViewerSidebarProps) {
   const { markEdited, addSources, recordAdded, removeSource } = editState;
   const addToView = useAddToView(bridge, {
@@ -40,7 +46,6 @@ export default function ViewerSidebar({
     onAddSources: addSources,
     onAdded: recordAdded
   });
-  const [tab, setTab] = useState('add');
   const sources = useViewSources(bridge, {
     viewLayers,
     added: editState.added,
@@ -139,7 +144,11 @@ export default function ViewerSidebar({
         {/* Content-width triggers, as in the Properties panel: MT measures
             the indicator only on window resize, so triggers that stretch
             with the panel, or wrap when it narrows, would leave it behind. */}
-        <Tabs className="min-w-0 flex-1" onValueChange={setTab} value={tab}>
+        <Tabs
+          className="min-w-0 flex-1"
+          onValueChange={value => onTabChange(value as SidebarTab)}
+          value={tab}
+        >
           <Tabs.List className="justify-start items-stretch shrink-0 min-w-fit w-full py-2 bg-surface dark:bg-surface-light">
             <Tabs.Trigger
               className="!text-foreground h-full whitespace-nowrap"