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Accessibility · Bootstrap
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< h1 class = "bd-title" id = "content" > Accessibility< / h1 >
< p class = "bd-lead" > A brief overview of Bootstrap's features and limitations for the creation of accessible content.< / p >
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< p > Bootstrap provides an easy-to-use framework of ready-made styles, layout tools, and interactive components, allowing developers to create websites and applications that are visually appealing, functionally rich, and accessible out of the box.< / p >
< h2 id = "overview-and-limitations" > Overview and Limitations< / h2 >
< p > The overall accessibility of any project built with Bootstrap depends in large part on the author’ ’ < a href = "https://www.w3.org/TR/WCAG20/" > < abbr title = "Web Content Accessibility Guidelines" > WCAG< / abbr > 2.0< / a > (A/AA/AAA), < a href = "https://www.section508.gov/" > Section 508< / a > and similar accessibility standards and requirements.< / p >
< h3 id = "structural-markup" > Structural markup< / h3 >
< p > Bootstrap’ < / p >
< h3 id = "interactive-components" > Interactive components< / h3 >
< p > Bootstrap’ < a href = "https://www.w3.org/WAI/intro/aria" > < abbr title = "Web Accessibility Initiative" > WAI< / abbr > -< abbr title = "Accessible Rich Internet Applications" > ARIA< / abbr > < / a > roles and attributes, these components should also be understandable and operable using assistive technologies (such as screen readers).< / p >
< p > Because Bootstrap’ < abbr title = "Accessible Rich Internet Applications" > ARIA< / abbr > roles and attributes, as well as JavaScript behavior, to more accurately convey the precise nature and functionality of their component. This is usually noted in the documentation.< / p >
< h3 id = "color-contrast" > Color contrast< / h3 >
< p > Most colors that currently make up Bootstrap’ < em > insufficient< / em > color contrast (below the recommended < a href = "https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html" > WCAG 2.0 color contrast ratio of 4.5:1< / a > ) when used against a light background. Authors will need to manually modify/extend these default colors to ensure adequate color contrast ratios.< / p >
< h3 id = "visually-hidden-content" > Visually hidden content< / h3 >
< p > Content which should be visually hidden, but remain accessible to assistive technologies such as screen readers, can be styled using the < code class = "highlighter-rouge" > .sr-only< / code > class. This can be useful in situations where additional visual information or cues (such as meaning denoted through the use of color) need to also be conveyed to non-visual users.< / p >
< figure class = "highlight" > < pre > < code class = "language-html" data-lang = "html" > < span class = "nt" > < p< / span > < span class = "na" > class=< / span > < span class = "s" > "text-danger"< / span > < span class = "nt" > > < / span >
< span class = "nt" > < span< / span > < span class = "na" > class=< / span > < span class = "s" > "sr-only"< / span > < span class = "nt" > > < / span > Danger: < span class = "nt" > < /span> < / span >
This action is not reversible
< span class = "nt" > < /p> < / span > < / code > < / pre > < / figure >
< p > For visually hidden interactive controls, such as traditional “skip” links, < code class = "highlighter-rouge" > .sr-only< / code > can be combined with the < code class = "highlighter-rouge" > .sr-only-focusable< / code > class. This will ensure that the control becomes visible once focused (for sighted keyboard users).< / p >
< figure class = "highlight" > < pre > < code class = "language-html" data-lang = "html" > < span class = "nt" > < a< / span > < span class = "na" > class=< / span > < span class = "s" > "sr-only sr-only-focusable"< / span > < span class = "na" > href=< / span > < span class = "s" > "#content"< / span > < span class = "nt" > > < / span > Skip to main content< span class = "nt" > < /a> < / span > < / code > < / pre > < / figure >
< h2 id = "additional-resources" > Additional resources< / h2 >
< ul >
< li > < a href = "https://www.w3.org/TR/WCAG20/" > Web Content Accessibility Guidelines (WCAG) 2.0< / a > < / li >
< li > < a href = "http://a11yproject.com/" > The A11Y Project< / a > < / li >
< li > < a href = "https://developer.mozilla.org/en-US/docs/Web/Accessibility" > MDN accessibility documentation< / a > < / li >
< li > < a href = "https://tenon.io/" > Tenon.io Accessibility Checker< / a > < / li >
< li > < a href = "https://www.paciellogroup.com/resources/contrastanalyser/" > Colour Contrast Analyser (CCA)< / a > < / li >
< li > < a href = "https://github.com/squizlabs/HTML_CodeSniffer" > “HTML Codesniffer” bookmarklet for identifying accessibility issues< / a > < / li >
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