diff --git a/frontend/src/components/modals/NodeModal.tsx b/frontend/src/components/modals/NodeModal.tsx
index 4e5e776..746fd01 100644
--- a/frontend/src/components/modals/NodeModal.tsx
+++ b/frontend/src/components/modals/NodeModal.tsx
@@ -43,13 +43,18 @@ export function NodeModal({ open, onClose, onSubmit, initial, title = 'Add Node'
   const [form, setForm] = useState<Partial<NodeData>>({ ...DEFAULT_DATA, ...initial })
   const [iconSearch, setIconSearch] = useState('')
   const [iconPickerOpen, setIconPickerOpen] = useState(false)
+  const [labelError, setLabelError] = useState(false)
 
   const set = (key: keyof NodeData, value: unknown) =>
     setForm((f) => ({ ...f, [key]: value }))
 
   const handleSubmit = (e: React.FormEvent) => {
     e.preventDefault()
-    if (!form.label?.trim()) return
+    if (!form.label?.trim()) {
+      setLabelError(true)
+      return
+    }
+    setLabelError(false)
     onSubmit(form)
     onClose()
   }
@@ -167,11 +172,11 @@ export function NodeModal({ open, onClose, onSubmit, initial, title = 'Add Node'
               <Label className="text-xs text-muted-foreground">Label *</Label>
               <Input
                 value={form.label ?? ''}
-                onChange={(e) => set('label', e.target.value)}
+                onChange={(e) => { set('label', e.target.value); if (labelError) setLabelError(false) }}
                 placeholder="My Server"
-                className="bg-[#21262d] border-[#30363d] text-sm h-8"
-                required
+                className={`bg-[#21262d] text-sm h-8 ${labelError ? 'border-[#f85149] focus-visible:ring-[#f85149]' : 'border-[#30363d]'}`}
               />
+              {labelError && <p className="text-[11px] text-[#f85149]">Label is required</p>}
             </div>
 
             {/* Hostname */}
diff --git a/frontend/src/components/modals/__tests__/NodeModal.test.tsx b/frontend/src/components/modals/__tests__/NodeModal.test.tsx
new file mode 100644
index 0000000..c45a498
--- /dev/null
+++ b/frontend/src/components/modals/__tests__/NodeModal.test.tsx
@@ -0,0 +1,65 @@
+import { describe, it, expect, vi } from 'vitest'
+import { render, screen, fireEvent } from '@testing-library/react'
+import { NodeModal } from '../NodeModal'
+
+describe('NodeModal', () => {
+  it('renders nothing when closed', () => {
+    const { container } = render(
+      <NodeModal open={false} onClose={vi.fn()} onSubmit={vi.fn()} />
+    )
+    expect(container.querySelector('[role="dialog"]')).toBeNull()
+  })
+
+  it('renders form fields when open', () => {
+    render(<NodeModal open onClose={vi.fn()} onSubmit={vi.fn()} />)
+    expect(screen.getByPlaceholderText('My Server')).toBeDefined()
+    expect(screen.getByText('Add Node')).toBeDefined()
+  })
+
+  it('does not call onSubmit when label is empty and shows error', () => {
+    const onSubmit = vi.fn()
+    render(<NodeModal open onClose={vi.fn()} onSubmit={onSubmit} />)
+    fireEvent.click(screen.getByText('Add'))
+    expect(onSubmit).not.toHaveBeenCalled()
+    expect(screen.getByText('Label is required')).toBeDefined()
+  })
+
+  it('calls onSubmit with form data when label is filled', () => {
+    const onSubmit = vi.fn()
+    const onClose = vi.fn()
+    render(<NodeModal open onClose={onClose} onSubmit={onSubmit} />)
+    fireEvent.change(screen.getByPlaceholderText('My Server'), { target: { value: 'My NAS' } })
+    fireEvent.click(screen.getByText('Add'))
+    expect(onSubmit).toHaveBeenCalledOnce()
+    expect(onSubmit.mock.calls[0][0].label).toBe('My NAS')
+    expect(onClose).toHaveBeenCalledOnce()
+  })
+
+  it('clears label error when user starts typing', () => {
+    render(<NodeModal open onClose={vi.fn()} onSubmit={vi.fn()} />)
+    fireEvent.click(screen.getByText('Add'))
+    expect(screen.getByText('Label is required')).toBeDefined()
+    fireEvent.change(screen.getByPlaceholderText('My Server'), { target: { value: 'x' } })
+    expect(screen.queryByText('Label is required')).toBeNull()
+  })
+
+  it('pre-fills form from initial prop', () => {
+    render(
+      <NodeModal open onClose={vi.fn()} onSubmit={vi.fn()} initial={{ label: 'Pre-filled', ip: '10.0.0.1' }} />
+    )
+    const input = screen.getByPlaceholderText('My Server') as HTMLInputElement
+    expect(input.value).toBe('Pre-filled')
+  })
+
+  it('shows Save button text when title is Edit Node', () => {
+    render(<NodeModal open onClose={vi.fn()} onSubmit={vi.fn()} title="Edit Node" />)
+    expect(screen.getByText('Save')).toBeDefined()
+  })
+
+  it('calls onClose when Cancel is clicked', () => {
+    const onClose = vi.fn()
+    render(<NodeModal open onClose={onClose} onSubmit={vi.fn()} />)
+    fireEvent.click(screen.getByText('Cancel'))
+    expect(onClose).toHaveBeenCalledOnce()
+  })
+})