![Tier 2 adaptive optimized icon](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/tier_2_icon.png)

TIER 2 --- [Adaptive app quality](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality) guidelines that prepare your app for
displays large and small.

![Depiction of three tiers with the middle tier, tier 2, highlighted.](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/tier_2_header.png)

ADAPTIVE OPTIMIZED APPS take advantage of the expansive displays of large screen
devices to provide a productive, engaging user experience.

Optimized apps are built with responsive/adaptive layouts that conform to
portrait and landscape orientations, multi‑window mode, and folded and
unfolded device states. Navigation rails and drawers enhance a user interface
that dynamically formats and positions elements such as buttons, text fields,
and dialogs for an optimal user experience.

Adaptive optimized apps provide support for keyboard navigation, keyboard
shortcuts, and mouse and trackpad zoom, *right‑click*, and hover behavior.

## Do's and don'ts

![](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/tier_2_do.png)  
check_circle

### Do

- Create two-pane layouts
- Use grid and column layouts
- Replace navigation bars with navigation rails and drawers
- Use activity embedding in legacy, multi-activity apps
- Support advanced keyboard, mouse, and trackpad functionality  
![](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/tier_2_dont.png)  
cancel

### Don't

- Stretch UI elements (text fields, buttons, dialogs) to fill extra space
- Stretch or crop images
- Make panels or sheets full width

## Guidelines

Follow the Tier 2 guidelines to optimize your apps for all form factors,
including large screens.  
![](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/ux_icon.svg)  

### [User interface](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#t2_user_interface)

Support screens of all sizes on devices of all kinds with responsive/adaptive layouts that provide an optimal user experience.  
Guidelines:

- [UI:Layouts](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#UI:Layouts)
- [UI:Elements](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#UI:Elements)
- [UI:Touch_Targets](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#UI:Touch_Targets)
- [UI:Focus](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#UI:Focus)  

#### What

App layouts conform to display dimensions. App UI includes:

- Leading-edge navigation rails and drawers
- Grid layouts that accommodate window size changes
- Column layouts
- Trailing-edge panels that are open by default on large screens

Two-pane layouts take advantage of large screen space. Multi‑activity apps implement activity embedding to create multi‑pane layouts of activities side by side.

Touch targets are large and reachable. Interactive drawables are focusable.  

#### Why

Large screen devices encompass a variety of form factors, including tablets, foldables, desktop computers, car displays, and XR. Display sizes vary. Devices are often---sometimes primarily---used in landscape orientation.  

#### How

See the [User interface](https://developer.android.com/guide/topics/large-screens/user-interface) overview.  
![](https://developer.android.com/static/images/guide/topics/large-screens/quality-guidelines/tier-2/mouse_and_trackpad_icon.svg)  

### [Keyboard, mouse, and trackpad](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#t2_keyboard_mouse_trackpad)

Support external hardware input devices to increase app usability and user satisfaction.  
Guidelines:

- [Input:Keyboard_Navigation](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Keyboard_Navigation)
- [Input:Keyboard_Shortcuts](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Keyboard_Shortcuts)
- [Input:Keyboard_Playback](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Keyboard_Playback)
- [Input:Keyboard_Send](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Keyboard_Send)
- [Input:Context_Menus](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Context_Menus)
- [Input:Zoom](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Zoom)
- [Input:Hover](https://developer.android.com/docs/quality-guidelines/adaptive-app-quality#Input:Hover)  

#### What

App provides enhanced support for keyboard, mouse, and trackpad input. Context menus are accessible by mouse and trackpad right‑click (secondary mouse button or secondary tap) behavior. App content can be zoomed using the mouse scroll wheel and trackpad pinch gestures. UI elements have hover states.  

#### Why

Peripherals such as keyboards, mice, and trackpads are often connected to large screen devices. ChromeOS devices typically have a built‑in keyboard and trackpad. Users are accustomed to using keyboard shortcuts, multiple mouse buttons, mouse scroll wheel, and trackpad gestures.  

#### How

See the [Keyboard, mouse, and trackpad](https://developer.android.com/guide/topics/large-screens/keyboard-mouse-and-trackpad-tier-2) overview.