Shared Web Experiences:
If you want current information on mobile accessibility — that is, people with disabilities using content on mobile devices, see https://www.w3.org/WAI/mobile/
This page is archived. We do not plan to update it. It was developed in 2008. Much of the information is still relevant today. It is useful for understanding that:
Many of the issues around designing for mobile devices are addressed by designing for people with disabilities.
When you address accessibility, you improve the mobile experience. This can help in presenting your business case for accessibility.
This page describes many of the barriers that people with disabilities
and people using mobile devices experience when interacting with web
content, including web applications. It shows how these barriers are
similarly addressed in W3C ’s Web Content
Accessibility Guidelines (WCAG), Mobile Web Best Practices, and Mobile
Web Application Best Practices.
Background
People with disabilities using computers have similar interaction
limitations as people without disabilities who are using mobile devices.
Both experience similar barriers when interacting with websites and web
applications. There is also significant overlap between the design
solutions for both. For more background, see:
A comprehensive comparison between MWBP and WCAG is provided in
Relationship between Mobile Web Best Practices (MWBP) and Web Content
Accessibility Guidelines (WCAG) .
Introduction
The barriers on this page are grouped under four principles:
perceivable, operable, understandable and robust. These principles lay
the foundation necessary for anyone to access and use web content, as
described in Understanding the Four Principles of
Accessibility
section of Introduction to Understanding WCAG 2.0. (Mobile devices vary
widely and not all the barriers are present on all models.)
This page includes links to some relevant solutions in:
The information below is also available in tabular
format .
Contents
Perceivable
Information and user interface components must be presentable to users
in ways they can perceive.
Experiences discussed below are also available in tabular
format .
Information conveyed solely with color
User perceives color incorrectly or not at all, and so misses or
misunderstands information or makes mistakes.
Disabilities Context: User who is blind or colorblind perceives
color incorrectly or not at all.
WCAG 1.0 checkpoint:
2.1
and
2.2 .
Mobile Context: Many screens have limited color palette and color
difference is not presented. Device is used in poor lighting (for
example, outdoors), so colors are not clearly perceived.
Large pages or large images
User only sees small areas at a time, is unable to relate different
areas of a page, and so becomes disoriented or has to scroll
excessively. Additionally, user cannot access picture details because
the picture is shrunk.
Disabilities Context: User with restricted field of vision or using
screen magnifier gets only small part of page or image at a time.
WCAG 1.0 checkpoint:
12.3 .
Mobile Context: Mobile device has small screen (viewport).
Audio-only prompts (beeps) for important information (warnings, errors)
User cannot operate or interact correctly with content, misses prompts,
makes mistakes.
Disabilities Context: User who is deaf or hard of hearing cannot
perceive content.
WCAG 1.0 checkpoint:
1.1
and
1.4 .
Mobile Context: Users often cannot hear in noisy (street, nightclub)
or in public places (trains, hotel lobbies).
Non-text objects (images, sound, video) with no text alternative
User cannot perceive important information or loses information due to
lack of alternative.
Disabilities Context: User who is blind cannot perceive content that
include non-text objects. Furthermore, information not available to user
whose browser, assistive technology, other user agent doesn’t support
object.
WCAG 1.0 checkpoint:
1.1 .
Mobile Context: User can be billed for download volume so images
might be turned off to save costs. Some mobile user agents have limited
support for non-text objects so user loses information. Some user agents
also shrunk images in size to fit the device’s screen which can make
images meaningless.
User has difficulty entering text so text is entered incorrectly or
mistakes are made.
Disabilities Context: User with motor disability (for example,
partial paralysis, hand tremor, lack of sensitivity, coordination) has
difficulty entering information.
Mobile Context: Device has small keypad which has limited
functionality compared to a full keyboard, or is held in an unsteady
hand.
Content formatted using tables or CSS, and reading order not correct when linearized (for example when CSS or tables not rendered)
User cannot understand the content correctly when it’s presented in a
linear order.
Disabilities Context: User who is blind reads content in document
tree order.
WCAG 1.0 checkpoint:
5.3 and
5.4 .
Mobile Context: Meaning of content can be changed because of
reformatting or restructuring in adaptation process.
Operable
User interface components and navigation must be operable.
Experiences discussed below are also available in tabular
format .
Mouse required for interaction and navigation
User is unable to navigate all content, or wastes time moving through
numerous links.
Disabilities Context: Some users with a motor disability cannot use
a mouse. Users who are blind also do not use the mouse.
Mobile Context: Device has no mouse, only alphanumeric keypad or
joystick.
Scripting required to operate content
User cannot operate the content so loses some information.
Disabilities Context: User’s assistive technology or browser doesn’t
support scripting.
Mobile Context: Scripting turned off or not supported.
User can not perceive content or can not operate interface.
Disabilities Context: Plugin turned off, or not installed, or not
compatible with assistive technology. Plugin not operable with preferred
input device.
WCAG 1.0 checkpoint:
11.1 .
Mobile Context: Plugin turned off, or not installed, or not
available; not compatible with input device (for example, requires
mouse).
Missing or inappropriate page title
User cannot easily scan to get an overview because of missing,
inappropriate, or long page title.
Disabilities Context: User who is blind typically uses a screen
reader feature to get a list of the currently open windows, by window
title. Therefore, if the page title is long, inappropriate or missing,
user cannot perceive the content.
WCAG 1.0 checkpoint:
13.2 .
Mobile Context: Page title truncated to fit narrow viewport of
mobile device.
Inconsistency between focus (tab) order and logical document content sequence
User is unable to navigate content in logical sequence, becomes
disoriented.
Disabilities Context: User with motor disability uses keyboard for
navigation not mouse. User who is blind also often use tab navigation to
move from one element to another.
WCAG 1.0 checkpoint:
9.4 .
Mobile Context: Mobile devices may not have a pointing device so the
user may have to navigate elements serially.
Non descriptive link label
User cannot determine to follow or not to follow a link because the link
label is not descriptive enough.
Disabilities Context: User can not determine purpose of a link when
read out of context. User who is blind often accesses a list of links on
a page without the context around them.
WCAG 1.0 checkpoint:
13.1 .
Mobile Context: User can not determine purpose of link.
Understandable
Information and the operation of user interface must be understandable.
Experiences discussed below are also available in tabular
format .
Long words, long and complex sentences, jargon
User has difficulty understanding information.
Disabilities Context: Users with some types of cognitive
disabilities have difficulty processing information. Users who are deaf
and whose native language is sign, have difficulty processing complex
written language.
WCAG 1.0 checkpoint:
14.1 .
Mobile Context: Text is displayed in small font, and user is often
distracted by ambient conditions (background noise, conversations,
moving objects in field of vision).
Blinking, moving, scrolling or auto-updating content
User has difficulty reading and comprehending content.
Disabilities Context: People with reading disabilities, cognitive
limitations, and learning disabilities do not have sufficient time to
read or comprehend information.
WCAG 1.0 checkpoint:
7.4 and
7.5 .
Mobile Context: Reduced size of mobile viewport or poor ambient
lighting makes it difficult to see content. Auto-refreshed pages may
also have cost implications if they are left open or put unnoticed into
the background.
Robust
Content must be robust enough that it can be interpreted reliably by a
wide variety of user agents, including assistive technologies.
Experiences discussed below are also available in tabular
format .
Invalid or unsupported markup
User cannot access the content because browser or adaptation system
chokes on markup or rejects or garbles it.
Disabilities Context: User’s assistive technology or browser cannot
handle markup.
Mobile Context: Some older mobile browsers do not display content
with invalid markup.
Scripting required to generate content
User cannot access the content so loses some information because
scripting is not supported by the user agent.
Disabilities Context: User’s assistive technology or browser doesn’t
support scripting.
WCAG 1.0 checkpoint:
6.3 .
Mobile Context: Scripting turned off or not supported.