diff --git a/src/components/__tests__/ErrorLayout.test.tsx b/src/components/__tests__/ErrorLayout.test.tsx
new file mode 100644
index 0000000..7fd2bf9
--- /dev/null
+++ b/src/components/__tests__/ErrorLayout.test.tsx
@@ -0,0 +1,85 @@
+// @vitest-environment happy-dom
+
+import '@testing-library/jest-dom/vitest'
+import React from 'react'
+import type { ReactNode } from 'react'
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import ErrorButton from '@/components/ErrorButton'
+import ErrorLayout from '@/components/ErrorLayout'
+
+vi.mock('next/link', () => ({
+  default: ({
+    href,
+    children,
+    className,
+  }: {
+    href: string
+    children: ReactNode
+    className?: string
+  }) => React.createElement('a', { href, className }, children),
+}))
+
+describe('ErrorLayout', () => {
+  it('renders error page content inside the shared layout shell', () => {
+    render(
+      React.createElement(
+        ErrorLayout,
+        null,
+        React.createElement('h1', null, 'Recoverable error'),
+      ),
+    )
+
+    expect(screen.getByRole('heading', { level: 1, name: 'Recoverable error' })).toBeInTheDocument()
+  })
+})
+
+describe('ErrorButton', () => {
+  it('renders an internal recovery link', () => {
+    render(React.createElement(ErrorButton, { href: '/dashboard' }, 'Dashboard'))
+
+    expect(screen.getByRole('link', { name: 'Dashboard' })).toHaveAttribute('href', '/dashboard')
+  })
+
+  it('renders an external support link safely', () => {
+    render(
+      React.createElement(
+        ErrorButton,
+        {
+          href: 'https://stellar.org/contact',
+          isExternal: true,
+          variant: 'secondary',
+        },
+        'Report Issue',
+      ),
+    )
+
+    const link = screen.getByRole('link', { name: 'Report Issue' })
+    expect(link).toHaveAttribute('href', 'https://stellar.org/contact')
+    expect(link).toHaveAttribute('target', '_blank')
+    expect(link).toHaveAttribute('rel', 'noopener noreferrer')
+  })
+
+  it('calls click handlers for button recovery actions', () => {
+    const onClick = vi.fn()
+
+    render(React.createElement(ErrorButton, { onClick }, 'Try Again'))
+
+    fireEvent.click(screen.getByRole('button', { name: 'Try Again' }))
+
+    expect(onClick).toHaveBeenCalledTimes(1)
+  })
+
+  it('supports disabled recovery buttons', () => {
+    const onClick = vi.fn()
+
+    render(React.createElement(ErrorButton, { onClick, disabled: true }, 'Retrying...'))
+
+    const button = screen.getByRole('button', { name: 'Retrying...' })
+    expect(button).toBeDisabled()
+
+    fireEvent.click(button)
+
+    expect(onClick).not.toHaveBeenCalled()
+  })
+})
diff --git a/tests/error-page.test.tsx b/tests/error-page.test.tsx
new file mode 100644
index 0000000..3777434
--- /dev/null
+++ b/tests/error-page.test.tsx
@@ -0,0 +1,54 @@
+// @vitest-environment happy-dom
+
+import '@testing-library/jest-dom/vitest'
+import React from 'react'
+import type { ReactNode } from 'react'
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import ErrorPage from '@/app/error'
+
+vi.mock('next/link', () => ({
+  default: ({
+    href,
+    children,
+    className,
+  }: {
+    href: string
+    children: ReactNode
+    className?: string
+  }) => React.createElement('a', { href, className }, children),
+}))
+
+describe('app error page', () => {
+  it('renders server error details and recovery actions', () => {
+    const reset = vi.fn()
+    const error = Object.assign(new Error('Database connection failed'), {
+      digest: 'ERR-123',
+    })
+
+    render(React.createElement(ErrorPage, { error, reset }))
+
+    expect(screen.getByText('500')).toBeInTheDocument()
+    expect(screen.getByRole('heading', { level: 1, name: 'Something Went Wrong' })).toBeInTheDocument()
+    expect(screen.getByText('Database connection failed')).toBeInTheDocument()
+    expect(screen.getByText('Error ID: ERR-123')).toBeInTheDocument()
+    expect(screen.getByRole('link', { name: 'Go Home' })).toHaveAttribute('href', '/')
+    expect(screen.getByRole('link', { name: 'Report Issue' })).toHaveAttribute(
+      'href',
+      'https://stellar.org/contact',
+    )
+
+    fireEvent.click(screen.getByRole('button', { name: 'Try Again' }))
+
+    expect(reset).toHaveBeenCalledTimes(1)
+  })
+
+  it('falls back when an error has no message', () => {
+    render(React.createElement(ErrorPage, {
+      error: Object.assign(new Error(''), { message: '' }),
+      reset: vi.fn(),
+    }))
+
+    expect(screen.getByText('An unexpected error occurred')).toBeInTheDocument()
+  })
+})
diff --git a/tests/network-error-page.test.tsx b/tests/network-error-page.test.tsx
new file mode 100644
index 0000000..68ed02a
--- /dev/null
+++ b/tests/network-error-page.test.tsx
@@ -0,0 +1,61 @@
+// @vitest-environment happy-dom
+
+import '@testing-library/jest-dom/vitest'
+import React from 'react'
+import type { ReactNode } from 'react'
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import NetworkError from '@/app/network-error/page'
+
+vi.mock('next/link', () => ({
+  default: ({
+    href,
+    children,
+    className,
+  }: {
+    href: string
+    children: ReactNode
+    className?: string
+  }) => React.createElement('a', { href, className }, children),
+}))
+
+describe('network error page', () => {
+  afterEach(() => {
+    vi.unstubAllGlobals()
+  })
+
+  it('renders troubleshooting guidance and recovery actions', () => {
+    render(React.createElement(NetworkError))
+
+    expect(screen.getByRole('heading', { level: 1, name: 'Connection Error' })).toBeInTheDocument()
+    expect(screen.getByRole('heading', { level: 2, name: 'What you can do:' })).toBeInTheDocument()
+    expect(screen.getByText("Check that you're connected to the internet")).toBeInTheDocument()
+    expect(screen.getByText('No internet connection detected')).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: 'Retry' })).toBeEnabled()
+    expect(screen.getByRole('link', { name: 'Go Home' })).toHaveAttribute('href', '/')
+  })
+
+  it('shows retrying status and disables retry while connectivity is being checked', () => {
+    vi.stubGlobal('fetch', vi.fn(() => new Promise<Response>(() => undefined)))
+
+    render(React.createElement(NetworkError))
+
+    fireEvent.click(screen.getByRole('button', { name: 'Retry' }))
+
+    expect(screen.getByText('Checking connection...')).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: 'Retrying...' })).toBeDisabled()
+  })
+
+  it('restores the idle status when the connectivity check fails', async () => {
+    vi.stubGlobal('fetch', vi.fn(() => Promise.reject(new Error('offline'))))
+
+    render(React.createElement(NetworkError))
+
+    fireEvent.click(screen.getByRole('button', { name: 'Retry' }))
+
+    await waitFor(() => {
+      expect(screen.getByText('No internet connection detected')).toBeInTheDocument()
+    })
+    expect(screen.getByRole('button', { name: 'Retry' })).toBeEnabled()
+  })
+})
diff --git a/tests/not-found-page.test.tsx b/tests/not-found-page.test.tsx
new file mode 100644
index 0000000..875967e
--- /dev/null
+++ b/tests/not-found-page.test.tsx
@@ -0,0 +1,60 @@
+// @vitest-environment happy-dom
+
+import '@testing-library/jest-dom/vitest'
+import React from 'react'
+import type { ReactNode } from 'react'
+import { fireEvent, render, screen } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import NotFound from '@/app/not-found'
+
+const routerBack = vi.fn()
+
+vi.mock('next/navigation', () => ({
+  useRouter: () => ({
+    back: routerBack,
+  }),
+}))
+
+vi.mock('next/link', () => ({
+  default: ({
+    href,
+    children,
+    className,
+  }: {
+    href: string
+    children: ReactNode
+    className?: string
+  }) => React.createElement('a', { href, className }, children),
+}))
+
+describe('not found page', () => {
+  beforeEach(() => {
+    routerBack.mockClear()
+  })
+
+  it('renders the 404 message, search input, and recovery links', () => {
+    render(React.createElement(NotFound))
+
+    expect(screen.getByText('404')).toBeInTheDocument()
+    expect(screen.getByRole('heading', { level: 1, name: 'Page Not Found' })).toBeInTheDocument()
+    expect(screen.getByPlaceholderText('Search the site...')).toBeInTheDocument()
+    expect(screen.getByRole('link', { name: 'Go Home' })).toHaveAttribute('href', '/')
+  })
+
+  it('routes back from the secondary recovery button', () => {
+    render(React.createElement(NotFound))
+
+    fireEvent.click(screen.getByRole('button', { name: 'Go Back' }))
+
+    expect(routerBack).toHaveBeenCalledTimes(1)
+  })
+
+  it('accepts search text in the site search box', () => {
+    render(React.createElement(NotFound))
+
+    const search = screen.getByPlaceholderText('Search the site...')
+    fireEvent.change(search, { target: { value: 'escrow status' } })
+
+    expect(search).toHaveValue('escrow status')
+  })
+})