<!DOCTYPE html><htmllang=en><head><metacharset=utf-8><metacontent="IE=edge"http-equiv=X-UA-Compatible><metacontent="width=device-width,initial-scale=1"name=viewport><metacontent="Bootstrap, a sleek, intuitive, and powerful mobile first front-end framework for faster and easier web development."name=description><metacontent="Mark Otto, Jacob Thornton, and Bootstrap contributors"name=author><title> Getting started · Bootstrap </title><linkhref=../dist/css/bootstrap.min.cssrel=stylesheet><linkhref=../assets/css/docs.min.cssrel=stylesheet><!--[if lt IE 9]><script src=../assets/js/ie8-responsive-file-warning.js></script><![endif]--><scriptsrc=../assets/js/ie-emulation-modes-warning.js></script><!--[if lt IE 9]> <script src=https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js></script> <script src=https://oss.maxcdn.com/respond/1.4.2/respond.min.js></script> <![endif]--><linkhref=/apple-touch-icon.pngrel=apple-touch-icon><linkhref=/favicon.icorel=icon><script>!function(e,t,a,n,c,o,s){e.GoogleAnalyticsObject=c,e[c]=e[c]||function(){(e[c].q=e[c].q||[]).push(arguments)},e[c].l=1*newDate,o=t.createElement(a),s=t.getElementsByTagName(a)[0],o.async=1,o.src=n,s.parentNode.insertBefore(o,s)}(window,document,"script","//www.google-analytics.com/analytics.js","ga"),ga("create","UA-146052-10","getbootstrap.com"),ga("send","pageview")</script></head><body><ahref=#contentclass="sr-only sr-only-focusable"id=skippy><divclass=container><spanclass=skiplink-text>Skip to main content</span></div></a><ahref=https://v4-alpha.getbootstrap.com/class=v4-tease>Aww yeah, Bootstrap 4 is coming!</a><headerclass="bs-docs-nav navbar navbar-static-top"id=top><divclass=container><divclass=navbar-header><buttonaria-controls=bs-navbararia-expanded=falseclass="collapsed navbar-toggle"data-target=#bs-navbardata-toggle=collapsetype=button><spanclass=sr-only>Toggle navigation</span><spanclass=icon-bar></span><spanclass=icon-bar></span><spanclass=icon-bar></span></button><ahref=../class=navbar-brand>Bootstrap</a></div><navclass="collapse navbar-collapse"id=bs-navbar><ulclass="nav navbar-nav"><liclass=active><ahref=../getting-started/>Getting started</a></li><li><ahref=../css/>CSS</a></li><li><ahref=../components/>Components</a></li><li><ahref=../javascript/>JavaScript</a></li><li><ahref=../customize/>Customize</a></li></ul><ulclass="nav navbar-nav navbar-right"><li><ahref=http://themes.getbootstrap.comonclick='ga("send","event","Navbar","Community links","Themes")'>Themes</a></li><li><ahref=https://jobs.getbootstrap.comonclick='ga("send","event","Navbar","Community links","Jobs")'>Jobs</a></li><li><ahref=http://expo.getbootstrap.comonclick='ga("send","event","Navbar","Community links","Expo")'>Expo</a></li><li><ahref=http://blog.getbootstrap.comonclick='ga("send","event","Navbar","Community links","Blog")'>Blog</a></li></ul></nav></div></header><divclass=bs-docs-headerid=contenttabindex=-1><divclass=container><h1>Getting started</h1><p>An overview of Bootstrap, how to download and use, basic templates and examples, and more.</p><divid=carbonads-container><divclass=carbonad><divid=azcarbon></div><script>varz=document.createElement("script");z.async=!0,z.src="http://engine.carbonads.com/z/32341/azcarbon_2_1_0_HORIZ";vars=document.getElementsByTagName("script")[0];s.parentNode.insertBefore(z,s)</script></div></div></div></div><divclass="container bs-docs-container"><divclass=row><divclass=col-md-9role=main><divclass=bs-docs-section><h1class=page-headerid=download>Download</h1><pclass=lead>Bootstrap (currently v3.3.7) has a few easy ways to quickly get started, each one appealing to a different skill level and use case. Read through to see what suits your particular needs.</p><divclass="row bs-downloads"><divclass=col-sm-4><h3id=download-bootstrap>Bootstrap</h3><p>Compiled and minified CSS, JavaScript, and fonts. No docs or original source files are included.</p><p><ahref=https://github.com/twbs/b
<spanclass=nt><script </span><spanclass=na>src=</span><spanclass=s>"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"</span><spanclass=na>integrity=</span><spanclass=s>"sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"</span><spanclass=na>crossorigin=</span><spanclass=s>"anonymous"</span><spanclass=nt>></script></span></code></pre></figure><h2id=download-bower>Install with Bower</h2><p>You can also install and manage Bootstrap's Less, CSS, JavaScript, and fonts using <ahref=http://bower.io>Bower</a>:</p><figureclass=highlight><pre><codeclass=language-bashdata-lang=bash><spanclass=gp>$ </span>bower install bootstrap</code></pre></figure><h2id=download-npm>Install with npm</h2><p>You can also install Bootstrap using <ahref=https://www.npmjs.com>npm</a>:</p><figureclass=highlight><pre><codeclass=language-bashdata-lang=bash><spanclass=gp>$ </span>npm install bootstrap@3</code></pre></figure><p><code>require('bootstrap')</code> will load all of Bootstrap's jQuery plugins onto the jQuery object. The <code>bootstrap</code> module itself does not export anything. You can manually load Bootstrap's jQuery plugins individually by loading the <code>/js/*.js</code> files under the package's top-level directory.</p><p>Bootstrap's <code>package.json</code> contains some additional metadata under the following keys:</p><ul><li><code>less</code> - path to Bootstrap's main <ahref=http://lesscss.org>Less</a> source file</li><li><code>style</code> - path to Bootstrap's non-minified CSS that's been precompiled using the default settings (no customization)</li></ul><h2id=download-composer>Install with Composer</h2><p>You can also install and manage Bootstrap's Less, CSS, JavaScript, and fonts using <ahref=https://getcomposer.org>Composer</a>:</p><figureclass=highlight><pre><codeclass=language-bashdata-lang=bash><spanclass=gp>$ </span>composer require twbs/bootstrap</code></pre></figure><h2id=download-autoprefixer>Autoprefixer required for Less/Sass</h2><p>Bootstrap uses <ahref=https://github.com/postcss/autoprefixer>Autoprefixer</a> to deal with <ahref=http://webdesign.about.com/od/css/a/css-vendor-prefixes.htm>CSS vendor prefixes</a>. If you're compiling Bootstrap from its Less/Sass source and not using our Gruntfile, you'll need to integrate Autoprefixer into your build process yourself. If you're using precompiled Bootstrap or using our Gruntfile, you don't need to worry about this because Autoprefixer is already integrated into our Gruntfile.</p></div><divclass=bs-docs-section><h1class=page-headerid=whats-included>What's included</h1><pclass=lead>Bootstrap is downloadable in two forms, within which you'll find the following directories and files, logically grouping common resources and providing both compiled and minified variations.</p><divclass="bs-callout bs-callout-warning"id=jquery-required><h4>jQuery required</h4><p>Please note that <strong>all JavaScript plugins require jQuery</strong> to be included, as shown in the <ahref=#template>starter template</a>. <ahref=https://github.com/twbs/bootstrap/blob/v3.3.7/bower.json>Consult our <code>bower.json</code></a> to see which versions of jQuery are supported.</p></div><h2id=whats-included-precompiled>Precompiled Bootstrap</h2><p>Once downloaded, unzip the compressed folder to see the structure of (the compiled) Bootstrap. You'll see something like this:</p><figureclass=highlight><pre><codeclass=language-bashdata-lang=bash>bootstrap/
└── glyphicons-halflings-regular.woff2</code></pre></figure><p>This is the most basic form of Bootstrap: precompiled files for quick drop-in usage in nearly any web project. We provide compiled CSS and JS (<code>bootstrap.*</code>), as well as compiled and minified CSS and JS (<code>bootstrap.min.*</code>). CSS <ahref=https://developer.chrome.com/devtools/docs/css-preprocessors>source maps</a> (<code>bootstrap.*.map</code>) are available for use with certain browsers' developer tools. Fonts from Glyphicons are included, as is the optional Bootstrap theme.</p><h2id=whats-included-source>Bootstrap source code</h2><p>The Bootstrap source code download includes the precompiled CSS, JavaScript, and font assets, along with source Less, JavaScript, and documentation. More specifically, it includes the following and more:</p><figureclass=highlight><pre><codeclass=language-bashdata-lang=bash>bootstrap/
└── examples/</code></pre></figure><p>The <code>less/</code>, <code>js/</code>, and <code>fonts/</code> are the source code for our CSS, JS, and icon fonts (respectively). The <code>dist/</code> folder includes everything listed in the precompiled download section above. The <code>docs/</code> folder includes the source code for our documentation, and <code>examples/</code> of Bootstrap usage. Beyond that, any other included file provides support for packages, license information, and development.</p></div><divclass=bs-docs-section><h1class=page-headerid=grunt>Compiling CSS and JavaScript</h1><pclass=lead>Bootstrap uses <ahref=http://gruntjs.com>Grunt</a> for its build system, with convenient methods for working with the framework. It's how we compile our code, run tests, and more.</p><h2id=grunt-installing>Installing Grunt</h2><p>To install Grunt, you must <strong>first <ahref=https://nodejs.org/download/>download and install node.js</a></strong> (which includes npm). npm stands for <ahref=https://www.npmjs.com/>node packaged modules</a> and is a way to manage development dependencies through node.js.</p> Then, from the command line: <ol><li>Install <code>grunt-cli</code> globally with <code>npm install -g grunt-cli</code>.</li><li>Navigate to the root <code>/bootstrap/</code> directory, then run <code>npm install</code>. npm will look at the <ahref=https://github.com/twbs/bootstrap/blob/master/package.json><code>package.json</code></a> file and automatically install the necessary local dependencies listed there.</li></ol><p>When completed, you'll be able to run the various Grunt commands provided from the command line.</p><h2id=grunt-commands>Available Grunt commands</h2><h3><code>grunt dist</code> (Just compile CSS and JavaScript)</h3><p>Regenerates the <code>/dist/</code> directory with compiled and minified CSS and JavaScript files. As a Bootstrap user, this is normally the command you want.</p><h3><code>grunt watch</code> (Watch)</h3><p>Watches the Less source files and automatically recompiles them to CSS whenever you save a change.</p><h3><code>grunt test</code> (Run tests)</h3><p>Runs <ahref=http://jshint.com>JSHint</a> and runs the <ahref=http://qunitjs.com>QUnit</a> tests headlessly in <ahref=http://phantomjs.org>PhantomJS</a>.</p><h3><code>grunt docs</code> (Build & test the docs assets)</h3><p>Builds and tests CSS, JavaScript, and other assets which are used when running the documentation locally via <code>bundle exec jekyll serve</code>.</p><h3><code>grunt</code> (Build absolutely everything and run tests)</h3><p>Compiles and minifies CSS and JavaScript, builds the documentation website, runs the HTML5 validator against the docs, regenerates the Customizer assets, and more. Requires <ahref=http://jekyllrb.com/docs/installation/>Jekyll</a>. Usually only necessary if you're hacking on Bootstrap itself.</p><h2id=grunt-troubleshooting>Troubleshooting</h2><p>Should you encounter problems with installing dependencies or running Grunt commands, first delete the <code>/node_modules/</code> directory generated by npm. Then, rerun <code>npm install</code>.</p></div><divclass=bs-docs-section><h1class=page-headerid=template>Basic template</h1><pclass=lead>Start with this basic HTML template, or modify <ahref=#examples>these examples</a>. We hope you'll customize our templates and examples, adapting them to suit your needs.</p><p>Copy the HTML below to begin working with a minimal Bootstrap document.</p><figureclass=highlight><pre><codeclass=language-htmldata-lang=html><spanclass=cp><!DOCTYPE html></span>
<spanclass=nt></html></span></code></pre></figure></div><divclass=bs-docs-section><h1class=page-headerid=examples>Examples</h1><pclass=lead>Build on the basic template above with Bootstrap's many components. We encourage you to customize and adapt Bootstrap to suit your individual project's needs.</p><p>Get the source code for every example below by <ahref=https://github.com/twbs/bootstrap/archive/v3.3.7.zip>downloading the Bootstrap repository</a>. Examples can be found in the <code>docs/examples/</code> directory.</p><h2id=examples-framework>Using the framework</h2><divclass="row bs-examples"><divclass="col-xs-6 col-md-4"><ahref=../examples/starter-template/class=thumbnail><imgalt="Starter template example"src=../examples/screenshots/starter-template.jpg></a><h3>Starter template</h3><p>Nothing but the basics: compiled CSS and JavaScript along with a container.</p></div><divclass="col-xs-6 col-md-4"><ahref=../examples/theme/class=thumbnail><imgalt="Bootstrap theme example"src=../examples/screenshots/theme.jpg></a><h3>Bootstrap theme</h3><p>Load the optional Bootstrap theme for a visually enhanced experience.</p></div><divclass="clearfix visible-xs"></div><divclass="col-xs-6 col-md-4"><ahref=../examples/grid/class=thumbnail><imgalt="Multiple grids example"src=../examples/screenshots/grid.jpg></a><h3>Grids</h3><p>Multiple examples of grid layouts with all four tiers, nesting, and more.</p></div><divclass="col-xs-6 col-md-4"><ahref=../examples/jumbotron/class=thumbnail><imgalt="Jumbotron example"src=../examples/screenshots/jumbotron.jpg></a><h3>Jumbotron</h3><p>Build around the jumbotron with a navbar and some basic grid columns.</p></div><divclass="clearfix visible-xs"></div><divclass="col-xs-6 col-md-4"><ahref=../examples/jumbotron-narrow/class=thumbnail><imgalt="Narrow jumbotron example"src=../examples/screenshots/jumbotron-narrow.jpg></a><h3>Narrow jumbotron</h3><p>Build a more custom page by narrowing the default container and jumbotron.</p></div></div><h2id=examples-navbars>Navbars in action</h2><divclass="row bs-examples"><divclass="col-xs-6 col-md-4"><ahref=../examples/navbar/class=thumbnail><imgalt="Navbar example"src=../examples/screenshots/navbar.jpg></a><h3>Navbar</h3><p>Super basic template that includes the navbar along with some additional content.</p></div><divclass="col-xs-6 col-md-4"><ahref=../examples/navbar-static-top/class=thumbnail><imgalt="Static top navbar example"src=../examples/screenshots/navbar-static.jpg></a><h3>Static top navbar</h3><p>Super basic template with a static top navbar along with some additional content.</p></div><divclass="clearfix visible-xs"></div><divclass="col-xs-6 col-md-4"><ahref=../examples/navbar-fixed-top/class=thumbnail><imgalt="Fixed navbar example"src=../examples/screenshots/navbar-fixed.jpg></a><h3>Fixed navbar</h3><p>Super basic template with a fixed top navbar along with some additional content.</p></div></div><h2id=examples-custom>Custom components</h2><divclass="row bs-examples"><divclass="col-xs-6 col-md-4"><ahref=../examples/cover/class=thumbnail><imgalt="A one-page template example"src=../examples/screenshots/cover.jpg></a><h3>Cover</h3><p>A one-page template for building simple and beautiful home pages.</p></div><divclass="col-xs-6 col-md-4"><ahref=../examples/carousel/class=thumbnail><imgalt="Carousel example"src=../examples/screenshots/carousel.jpg></a><h3>Carousel</h3><p>Customize the navbar and carousel, then add some new components.</p></div><divclass="clearfix visible-xs"></div><divclass="col-xs-6 col-md-4"><ahref=../examples/blog/class=thumbnail><imgalt="Blog layout example"src=../examples/screenshots/blog.jpg></a><h3>Blog</h3><p>Simple two-column blog layout with custom navigation, header, and type.</p></div><divclass="col-xs-6 col-md-4"><ahref=../examples/dashboard/class=thumbnail><imgalt="Dashboard example"src=../examples/screenshots/dashboard.jpg></a><h3>Dashboard</h3><
<spanclass=p>}</span></code></pre></figure><p>For more information and usage guidelines, read <ahref=http://timkadlec.com/2013/01/windows-phone-8-and-device-width/>Windows Phone 8 and Device-Width</a>.</p><p>As a heads up, we include this in all of Bootstrap's documentation and examples as a demonstration.</p><h2id=support-safari-percentages>Safari percent rounding</h2><p>The rendering engine of versions of Safari prior to v7.1 for OS X and Safari for iOS v8.0 had some trouble with the number of decimal places used in our <code>.col-*-1</code> grid classes. So if you had 12 individual grid columns, you'd notice that they came up short compared to other rows of columns. Besides upgrading Safari/iOS, you have some options for workarounds:</p><ul><li>Add <code>.pull-right</code> to your last grid column to get the hard-right alignment</li><li>Tweak your percentages manually to get the perfect rounding for Safari (more difficult than the first option)</li></ul><h2id=support-fixed-position-keyboards>Modals, navbars, and virtual keyboards</h2><h3>Overflow and scrolling</h3><p>Support for <code>overflow: hidden</code> on the <code><body></code> element is quite limited in iOS and Android. To that end, when you scroll past the top or bottom of a modal in either of those devices' browsers, the <code><body></code> content will begin to scroll. See <ahref="https://bugs.chromium.org/p/chromium/issues/detail?id=175502">Chrome bug #175502</a> (fixed in Chrome v40) and <ahref="https://bugs.webkit.org/show_bug.cgi?id=153852">WebKit bug #153852</a>.</p><h3>iOS text fields and scrolling</h3><p>As of iOS 9.3, while a modal is open, if the initial touch of a scroll gesture is within the boundary of a textual <code><input></code> or a <code><textarea></code>, the <code><body></code> content underneath the modal will be scrolled instead of the modal itself. See <ahref="https://bugs.webkit.org/show_bug.cgi?id=153856">WebKit bug #153856</a>.</p><h3>Virtual keyboards</h3><p>Also, note that if you're using a fixed navbar or using inputs within a modal, iOS has a rendering bug that doesn't update the position of fixed elements when the virtual keyboard is triggered. A few workarounds for this include transforming your elements to <code>position: absolute</code> or invoking a timer on focus to try to correct the positioning manually. This is not handled by Bootstrap, so it is up to you to decide which solution is best for your application.</p><h3>Navbar Dropdowns</h3><p>The <code>.dropdown-backdrop</code> element isn't used on iOS in the nav because of the complexity of z-indexing. Thus, to close dropdowns in navbars, you must directly click the dropdown element (or <ahref=https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile>any other element which will fire a click event in iOS</a>).</p><h2id=support-browser-zooming>Browser zooming</h2><p>Page zooming inevitably presents rendering artifacts in some components, both in Bootstrap and the rest of the web. Depending on the issue, we may be able to fix it (search first and then open an issue if need be). However, we tend to ignore these as they often have no direct solution other than hacky workarounds.</p><h2id=support-sticky-hover-mobile>Sticky <code>:hover</code>/<code>:focus</code> on mobile</h2><p>Even though real hovering isn't possible on most touchscreens, most mobile browsers emulate hovering support and make <code>:hover</code> "sticky". In other words, <code>:hover</code> styles start applying after tapping an element and only stop applying after the user taps some other element. This can cause Bootstrap's <code>:hover</code> states to become undesirably "stuck" on such browsers. Some mobile browsers also make <code>:focus</code> similarly sticky. There is currently no simple workaround for these issues other than removing such styles entirely.</p><h2id=support-printing>Printing</h2><p>Even in some modern browsers, printing can be quirky.</p><p>In particular, as of Chrome v32 and regardless of margin settin
<spanclass=p>}</span></code></pre></figure><h2id=support-android-stock-browser>Android stock browser</h2><p>Out of the box, Android 4.1 (and even some newer releases apparently) ship with the Browser app as the default web browser of choice (as opposed to Chrome). Unfortunately, the Browser app has lots of bugs and inconsistencies with CSS in general.</p><h3>Select menus</h3><p>On <code><select></code> elements, the Android stock browser will not display the side controls if there is a <code>border-radius</code> and/or <code>border</code> applied. (See <ahref=https://stackoverflow.com/questions/14744437/html-select-box-not-showing-drop-down-arrow-on-android-version-4-0-when-set-with>this StackOverflow question</a> for details.) Use the snippet of code below to remove the offending CSS and render the <code><select></code> as an unstyled element on the Android stock browser. The user agent sniffing avoids interference with Chrome, Safari, and Mozilla browsers.</p><figureclass=highlight><pre><codeclass=language-htmldata-lang=html><spanclass=nt><script></span>
<spanclass=nt></script></span></code></pre></figure><p>Want to see an example? <ahref=http://jsbin.com/kuvoz/1>Check out this JS Bin demo.</a></p><h2id=support-validators>Validators</h2><p>In order to provide the best possible experience to old and buggy browsers, Bootstrap uses <ahref=http://browserhacks.com>CSS browser hacks</a> in several places to target special CSS to certain browser versions in order to work around bugs in the browsers themselves. These hacks understandably cause CSS validators to complain that they are invalid. In a couple places, we also use bleeding-edge CSS features that aren't yet fully standardized, but these are used purely for progressive enhancement.</p><p>These validation warnings don't matter in practice since the non-hacky portion of our CSS does fully validate and the hacky portions don't interfere with the proper functioning of the non-hacky portion, hence why we deliberately ignore these particular warnings.</p><p>Our HTML docs likewise have some trivial and inconsequential HTML validation warnings due to our inclusion of a workaround for <ahref="https://bugzilla.mozilla.org/show_bug.cgi?id=654072">a certain Firefox bug</a>.</p></div><divclass=bs-docs-section><h1class=page-headerid=third-parties>Third party support</h1><pclass=lead>While we don't officially support any third party plugins or add-ons, we do offer some useful advice to help avoid potential issues in your projects.</p><h2id=third-box-sizing>Box-sizing</h2><p>Some third party software, including Google Maps and Google Custom Search Engine, conflict with Bootstrap due to <code>* { box-sizing: border-box; }</code>, a rule which makes it so <code>padding</code> does not affect the final computed width of an element. Learn more about <ahref=https://css-tricks.com/box-sizing/>box model and sizing at CSS Tricks</a>.</p><p>Depending on the context, you may override as-needed (Option 1) or reset the box-sizing for entire regions (Option 2).</p><figureclass=highlight><pre><codeclass=language-scssdata-lang=scss><spanclass=cm>/* Box-sizing resets
<spanclass=p>}</span></code></pre></figure></div><divclass=bs-docs-section><h1class=page-headerid=accessibility>Accessibility</h1><pclass=lead>Bootstrap follows common web standards and—with minimal extra effort—can be used to create sites that are accessible to those using <abbrtitle="Assistive Technology"class=initialism>AT</abbr>.</p><h2>Skip navigation</h2><p>If your navigation contains many links and comes before the main content in the DOM, add a <code>Skip to main content</code> link before the navigation (for a simple explanation, see this <ahref=http://a11yproject.com/posts/skip-nav-links>A11Y Project article on skip navigation links</a>). Using the <code>.sr-only</code> class will visually hide the skip link, and the <code>.sr-only-focusable</code> class will ensure that the link becomes visible once focused (for sighted keyboard users).</p><divclass="bs-callout bs-callout-danger"id=callout-skiplinks><p>Due to long-standing shortcomings/bugs in Chrome (see <ahref="https://code.google.com/p/chromium/issues/detail?id=262171"title="Chromium bug tracker - Issue 262171: Focus should cycle from named anchor">issue 262171 in the Chromium bug tracker</a>) and Internet Explorer (see this article on <ahref=http://accessibleculture.org/articles/2010/05/in-page-links/>in-page links and focus order</a>), you will need to make sure that the target of your skip link is at least programmatically focusable by adding <code>tabindex="-1"</code>.</p><p>In addition, you may want to explicitly suppress a visible focus indication on the target (particularly as Chrome currently also sets focus on elements with <code>tabindex="-1"</code> when they are clicked with the mouse) with <code>#content:focus { outline: none; }</code>.</p><p>Note that this bug will also affect any other in-page links your site may be using, rendering them useless for keyboard users. You may consider adding a similar stop-gap fix to all other named anchors / fragment identifiers that act as link targets.</p></div><figureclass=highlight><pre><codeclass=language-htmldata-lang=html><spanclass=nt><body></span>
<spanclass=nt><a</span><spanclass=na>href=</span><spanclass=s>"#content"</span><spanclass=na>class=</span><spanclass=s>"sr-only sr-only-focusable"</span><spanclass=nt>></span>Skip to main content<spanclass=nt></a></span>
<spanclass=nt></body></span></code></pre></figure><h2>Nested headings</h2><p>When nesting headings (<code><h1></code> - <code><h6></code>), your primary document header should be an <code><h1></code>. Subsequent headings should make logical use of <code><h2></code> - <code><h6></code> such that screen readers can construct a table of contents for your pages.</p><p>Learn more at <ahref=http://squizlabs.github.io/HTML_CodeSniffer/Standards/Section508/>HTML CodeSniffer</a> and <ahref=http://accessibility.psu.edu/headings>Penn State's AccessAbility</a>.</p><h2>Color contrast</h2><p>Currently, some of the default color combinations available in Bootstrap (such as the various <ahref=../css/#buttons>styled button</a> classes, some of the code highlighting colors used for <ahref=../css/#code-block>basic code blocks</a>, the <code>.bg-primary</code><ahref=../css/#helper-classes-backgrounds>contextual background</a> helper class, and the default link color when used on a white background) have a low contrast ratio (below the <ahref=http://www.w3.org/TR/WCAG20/#visual-audio-contrast-contrast>recommended ratio of 4.5:1</a>). This can cause problems to users with low vision or who are color blind. These default colors may need to be modified to increase their contrast and legibility.</p><h2>Additional resources</h2><ul><li><ahref=https://github.com/squizlabs/HTML_CodeSniffer>"HTML Codesniffer" bookmarklet for identifying accessibility issues</a></li><li><ahref="https://chrome.google.com/webstore/detail/accessibility-developer-t/fpkknkljclfencbdbgkenhalefipecmb?hl=en">Chrome's Accessibility Developer Tools extension</a></li><li><ahref=http://www.paciellogroup.com/resources/contrastanalyser/>Colour Contrast Analyser</a></li><li><ahref=http://a11yproject.com/>The A11Y Project</a></li><li><ahref=https://developer.mozilla.org/en-US/docs/Accessibility>MDN accessibility documentation</a></li></ul></div><divclass=bs-docs-section><h1class=page-headerid=license-faqs>License FAQs</h1><pclass=lead>Bootstrap is released under the MIT license and is copyright 2016 Twitter. Boiled down to smaller chunks, it can be described with the following conditions.</p><h2>It requires you to:</h2><ul><li>Keep the license and copyright notice included in Bootstrap's CSS and JavaScript files when you use them in your works</li></ul><h2>It permits you to:</h2><ul><li>Freely download and use Bootstrap, in whole or in part, for personal, private, company internal, or commercial purposes</li><li>Use Bootstrap in packages or distributions that you create</li><li>Modify the source code</li><li>Grant a sublicense to modify and distribute Bootstrap to third parties not included in the license</li></ul><h2>It forbids you to:</h2><ul><li>Hold the authors and license owners liable for damages as Bootstrap is provided without warranty</li><li>Hold the creators or copyright holders of Bootstrap liable</li><li>Redistribute any piece of Bootstrap without proper attribution</li><li>Use any marks owned by Twitter in any way that might state or imply that Twitter endorses your distribution</li><li>Use any marks owned by Twitter in any way that might state or imply that you created the Twitter software in question</li></ul><h2>It does not require you to:</h2><ul><li>Include the source of Bootstrap itself, or of any modifications you may have made to it, in any redistribution you may assemble that includes it</li><li>Submit changes that you make to Bootstrap back to the Bootstrap project (though such feedback is encouraged)</li></ul><p>The full Bootstrap license is located <ahref=https://github.com/twbs/bootstrap/blob/master/LICENSE>in the project repository</a> for more information.</p></div><divclass=bs-docs-section><h1class=page-headerid=translations>Translations</h1><pclass=lead>Community members have translated Bootstrap's documentation into various languages. None are officially supported and they may not always be up to date.</p><ul><li><ahref=http://v3.bootcss.com/
