--- title: Accessibility ---
Care about accessibility or want to contribute? Submit a Pull Request or get into the conversation on GitHub.
*** ## Basic Concepts - OverviewThe most common impairments for web users are those with problems seeing, hearing or a physical inability to use a mouse. For that reason, the site must be navigatable by keyboard. Most commonly the tab key is used to tab through the content. For a vision impaired person will have a screenreader installed that reads the content out loud. We used Chromevox to test with. You can find a list of popular screen readers below in the resource list.
### Tab-indexTab index lets users move forward and backward through the links and form elements on a page. But you can make anything "tabbable" with the tabindex attribute. {{#markdown}} ```html
As the numbers suggest, tapping on the tab key takes users through anything with the tabindex attribute in order. In HTML5, you can use it on any element. That means you can set priorities quickly. Want to help people get past the same tedious navigation they get on every page? Use tabindex to put navigation last.
Tip: When starting out use sets of 10: tabindex="10", tabindex="20", tabindex="30". If you decide to rearrange the order — say, put the third item between the first and second — you don't have to rearrange everything. Just make it tabindex="15".
### How to Test a Website’s Keyboard AccessibilityOn a desktop or laptop in Firefox, IE, Chrome, or Safari, click into the browser address bar.
Take your hand off your mouse and use only your keyboard. Using the Tab button, navigate until you’ve reached the link below. (You can use Shift+Tab to navigate back one step.)
Give the person the ability to skip the navigation at the top of the page. If you have menu with 40 links, you can imagine how long it would take someone to tab through all that. Here's one way to do it:
Note: A person who can see may be slightly confused that their focus is off screen. This is a minor compromise for this method.
*** ### Nested HeadingsWhen nesting headings `