skills/android-native-dev/references/accessibility.md

Accessibility Guidelines

Comprehensive accessibility requirements for Android applications.

Core Requirements

Minimum Standards

Requirement	Specification
Color contrast (text)	4.5:1 minimum
Color contrast (large text)	3:1 minimum
Color contrast (UI components)	3:1 minimum
Touch targets	48 × 48dp minimum
Content descriptions	All interactive elements
Focus indicators	Clearly visible
Screen reader support	Proper semantics

Content Labels

contentDescription

Use for non-text interactive elements.

When to use:

• ImageView, ImageButton
• CheckBox, Switch (state description)
• Custom drawable views
• Icons that convey meaning

When NOT to use:

• TextView (uses text content automatically)
• Decorative images (set to null)
• Elements with labelFor relationship

android:hint

Use for editable text fields to show placeholder text.

Important: Don't use contentDescription on EditText—it interferes with accessibility services.

android:labelFor

Link labels to input fields by setting labelFor on the TextView to reference the EditText ID.

Label Best Practices

Do's

Practice	Example
Be concise	"Save" not "Click here to save"
Describe action/purpose	"Delete message"
Be unique in context	"Delete item 3" not just "Delete"
Update dynamically	"Pause" ↔ "Play" based on state

Don'ts

Avoid	Reason
Include element type	TalkBack announces "button" automatically
Say "button", "image", etc.	Redundant with accessibility info
Use "click" or "tap"	Input method varies
Leave empty/generic	"Button" or "Image" is unhelpful

Examples

Bad	Good
"Save button"	"Save"
"Click here to submit"	"Submit"
"Image"	"Profile photo of John"
"Button 1"	"Add to cart"

Focus and Navigation

Focus Groups

Group related elements using screenReaderFocusable="true" on the container and focusable="false" on child elements. TalkBack will announce all children's content in a single utterance.

Headings

Mark section headers with accessibilityHeading="true". Users can navigate between headings for quick scanning.

Pane Titles

Identify screen regions with accessibilityPaneTitle. Accessibility services announce pane changes.

Focus Order

• Natural reading order (top-to-bottom, start-to-end)
• Use accessibilityTraversalBefore/After for custom order
• Ensure all interactive elements are focusable
• Skip decorative elements

Decorative Elements

Skip elements that don't convey information:

• Set contentDescription="@null"
• Or set importantForAccessibility="no"

Custom Accessibility Actions

Adding Actions

Provide alternatives for gesture-based interactions using ViewCompat.addAccessibilityAction(). This exposes swipe actions to accessibility services.

Replacing Action Labels

Make default actions more descriptive using ViewCompat.replaceAccessibilityAction(). Example: "Double tap and hold to add to favorites" instead of generic "long press".

Color and Visual Cues

Don't Rely on Color Alone

Combine color with other indicators:

Information	Color + Alternative
Error state	Red + error icon + text
Success	Green + checkmark + text
Required field	Red asterisk + "Required" label
Selected item	Highlight + checkmark + bold
Link text	Blue + underline

Contrast Testing

Use tools to verify contrast:

• Android Accessibility Scanner
• Contrast Checker plugins
• Manual calculation: (L1 + 0.05) / (L2 + 0.05)

Touch Targets

Minimum Sizes

Element	Minimum	Recommended
Standard	48 × 48dp	48 × 48dp
Primary actions	48 × 48dp	56 × 56dp
Kids apps	56 × 56dp	64 × 64dp

Spacing

• Minimum 8dp between adjacent touch targets
• Visual element can be smaller if touch area is adequate (use padding)

Screen Reader Announcements

Live Regions

Announce dynamic content changes using accessibilityLiveRegion:

Mode	Usage
polite	Announces when user is idle
assertive	Interrupts current speech
none	No automatic announcements

Custom Announcements

Use announceForAccessibility() sparingly—prefer live regions.

Keyboard and Hardware Navigation

Focus Indicators

• Visible focus state for all interactive elements
• Don't remove default focus indicators
• Custom focus: 2dp+ border or background change

Keyboard Shortcuts

• Support Tab navigation
• Enter/Space for activation
• Arrow keys for lists/grids
• Escape for dismissal

Testing Accessibility

Manual Testing

1. TalkBack: Navigate entire app with screen reader
2. Switch Access: Test with switch navigation
3. Keyboard: Navigate with external keyboard only
4. Magnification: Test with zoom enabled
5. Large text: Test with 200% font scale
6. High contrast: Test with high contrast mode

Automated Testing

Tool	Purpose
Accessibility Scanner	On-device scanning
Espresso Accessibility Checks	Automated UI tests
Lint checks	Static analysis

Checklist

• All interactive elements have descriptions
• Touch targets are 48dp minimum
• Color contrast meets requirements
• Focus order is logical
• Headings are properly marked
• Custom actions have descriptive labels
• Live regions announce important changes
• Keyboard navigation works
• Works with TalkBack enabled
• Works with large text (200%)