Your website content must also be fully accessible on mobile devices, including users who rely on using a mobile screen reader.  

iOS and Android mobile devices both have built in screen readers. 

Mobile screen reader users use swiping and tapping gestures to navigate websites on mobile devices.

Mobile accessibility best practices

Following are some mobile accessibility best practices.

1  Provide easy tap/touch targets

Tap targets within an app should be big enough for people to interact with precision.

Touch targets should be at least 9 mm high by 9 mm wide. Mobile applications should also position interactive elements where they can be easily reached regardless of how the device is held. 

2  Provide sufficient color contrast

Extra attention must be paid to mobile devices when it comes to color contrast. 

Mobile devices are more likely to be used outdoors, where glare from the sun could impact ability to see the screen. 

Text legibility should be preserved by an adequate contrast between the font color and the background. 

For WCAG 2.1 AA compliance, text should have a color contrast ratio of at least 4.5:1 (larger text at least 3:1). 

Allowing different contrast ratios for larger text is useful because wider character strokes are easier to read at a lower contrast than narrower character strokes. 

3   Make it easy for users to enter data 

Reduce the amount of text entry required by providing select menus, radio buttons, or check boxes, or by auto filling known information (e.g., date, time, location).

4. Create a logical reading/tap order for screen reader users

Create a logical reading/tap order for screen reader users.

Place submit buttons for forms, etc, in context of actions performed within the content area

The screen reader will read from top to bottom of the screen.

5. Provide users with the ability to display content in their preferred orientation

Ensure that content displays in the orientation (portrait or landscape) preferred by the user, including on a mobile device.

6. Provide users with the ability to control text size

Allow the user to control the text size on mobile devices with small screens.

7. Steer away from using PDF documents

Unlike web pages, PDF documents are not responsive and do not adjust to your screen size, such as on a mobile device. This forces the user to have to zoom in and the swipe left to right /right to left in order to read the content.

8. Keyboard related guidelines for touchscreen devices

Allow mobile devices to be operated by external physical keyboards or alternative on-screen keyboards.

Ensure that content accessed through a mobile device does not "trap" keyboard focus within subsections of content.

Ensure that when mobile keyboard users or mobile screen reader users navigate sequentially through content on a mobile device, they encounter information in an order that is consistent with the meaning of the content.

Help mobile keyboard users and mobile screen reader users know which element has the keyboard focus.

9. Navigation and consistency

Ensure that navigational mechanisms on a mobile screen, that are repeated on multiple web pages within a set of web pages, occur in the same relative order each time they are repeated.

Ensure that components viewed on a mobile device, that have the same functionality within a set of web pages, are identified consistently.

10. Links and grouping of operable elements that perform the same action

When multiple elements perform the same action or go to the same destination (e.g. link icon with link text), these should be contained within the same actionable element. This increases the touch target size for all users. It also reduces the number of redundant focus targets, which benefits people using screen readers and keyboard/switch control.

Help users understand the purpose of each link when viewed on a mobile device.

Help users understand the purpose of each link from the link text alone when viewed on a mobile device.

11. Labels and instructions

Ensure that labels or instructions are provided to mobile users and mobile screen reader users when content requires user input.

12. Operating touch screens

Provide users with the ability to operate touchscreens with one finger and reduced gestures.

WCAG Mobile Related Guidelines

WCAG 2.0 Guidelines Related to Mobile Accessibility

Testing with mobile screen readers

Mobile screen reader users use swiping and tapping gestures to navigate websites on mobile devices.

VoiceOver on iOS

You can turn VoiceOver on by going to “Settings” > “General” > “Accessibility” > “VoiceOver”. 

You can also access the VoiceOver tutorial, as well as the VoiceOver settings, from there as well.

VoiceOver/iOS Gestures

Gesture

Action

Touch/single tap

Select and read the element

Double-tap

Activate the selected element

Swipe-right

Move to next the element

Swipe-left

Move to previous the element

Swipe up or down

On an adjustable element like a slider, this increments or decrements the value. In text view, this moves the insertion point backwards or forwards.

Double press: with one finger, perform a double tap. During the second tap, continue to hold your finger against the screen.

Drag the selected item

Two-finger tap

Pause/resume reading

Two-finger swipe up

Read all accessible items from the top of the screen

Two-finger swipe down

Read all accessible items from the current position

Two-finger pinch open/closed

Select/deselect text

Three-finger swipe up/down

Scroll screen up/down

Three-finger swipe left/right

Navigate to the next/previous page

Three-finger double tap (if zoom is enabled, this becomes a three-finger triple tap)

Toggle speech

Three-finger triple tap (if zoom is enabled, this becomes a three-finger quadruple tap)

Toggle screen curtain

Four-finger tap at the top or bottom of the screen

Select the first or last accessible element on the screen

TalkBack on Android

To turn on TalkBack, go to the “Accessibility” option under “Settings.” 

There’s also an option you can enable to toggle TalkBack on and off, along with a lot of other accessibility options.

TalkBack/Android Gestures

Gesture

Action

Touch/single tap

Read element

Double-tap

Activate element

Swipe-right

Move to next element

Swipe-left

Move to previous element

Two-finger slide up/down

Scroll

Triple-tap

Zoom

Slide up-down

Jump to the first item on the screen

Slide down-up

Jump to the last item on the screen

Slide left-right

Scroll up one screen

Slide right-left

Scroll down one screen

Slide up-left

Return to the home screen (from anywhere)

Slide down-left

Activate the back button (browser only), close app (apps only)

Slide up-right

Opens the local context menu (options depend on where you are)

Slide down-right

Opens the global context menu (includes TalkBack settings)