Web accessibility means creating digital resources on the web that everyone can use. This involves creating a web that is accessible to people with disabilities that may affect how they use the Web, including but not limited to visual, auditory, physical, speech, cognitive and neurological disabilities.
An accessible web benefits everyone. People with or without disabilities. Web users and web developers. People with diverse needs and preferences. An accessible web gives people the flexibility to access digital materials in whatever way they need.
Screen reader users can use heading structure to navigate content. By using headings (<h1>, <h2>, etc.) correctly and strategically, the content of your website will be well-organized and easily interpreted by screen readers. HTML 5 standard provides many more semantic mark-up techniques.
Be sure to adhere to the correct order of headings, and separate presentation from structure by using CSS (Cascading Style Sheets). Do not pick a header just because it looks good visually (which can confuse screen reader users); instead, create a new CSS class to style your text.
Examples of proper use of headings:
Use <h1> for the primary title of the page. Avoid using an <h1> for anything other than the title of the website and the title of individual pages.
Use headings to indicate and organize your content structure.
Do not skip heading levels (e.g., go from an <h1> to an <h3>), as screen reader users will wonder if content is missing.
Alt text should be provided for images, so that screen reader users can understand the message conveyed by the use of images on the page. This is especially important for informative images (such as infographics). When creating the alt text, the text should contain the message you wish to convey through that image, and if the image includes text, that text should also be included in the alt.
The exception to this rule is when an image is used purely for decoration; in this case, the alt text can be left empty so that the screen reader user is not distracted from the more important content on the page.
If an image is the only content of a link, the screen reader will read the file name if alt text is not provided. Always provide alt text for images that are used as links.
When including links in your content, use text that properly describes where the link will go. Using "click here" is not considered descriptive and is ineffective for a screen reader user.
Just like sighted users scan the page for linked text, visually-impaired users can use their screen readers to scan for links. As a result, screen reader users often do not read the link within the context of the rest of the page. Using descriptive text properly explains the context of links to the screen reader user.
The most unique content of the link should be presented first, as screen reader users will often navigate the links list by searching via the first letter.
For example, if you are pointing visitors to a page called "About Us":
Try not to say: "Click here to read about our company."
Instead, say: "To learn more about our company, read About Us."
The most common form of color deficiency, red-green color deficiency, affects approximately 8% of the population. Using ONLY colors such as these (especially to indicate required fields in a form) will prevent these individuals from understanding your message.
Other groups of people with disabilities, particularly users with learning disabilities, benefit greatly from color when used to distinguish and organize your content.
To satisfy both groups, use color, but also be sure to use other visual indicators, such as an asterisk or question mark. Be sure to also distinguish blocks of content from one another using visual separation (such as white space or borders).
There are several tools you can use to evaluate color contrast, which will assist you in making your page as visually usable as possible to individuals with low vision or varying levels of color blindness.
When form fields are not labeled appropriately, the screen reader user does not have the same cues available as the sighted user. It may be impossible to tell what type of content should be entered into a form field.
Each field in your form should have a well-positioned, descriptive label. For example, if the field is for a person's name, it should be labeled appropriately as either "Full Name" or have two separate fields labeled as "First Name" and "Last Name." Use the <label> tag or an ARIA property (see tip #9) to associate the label text with the form field.
As you are going through a form field, a person should be able to tab through the form and fill out all the fields before getting to the "Submit" button, or they may not even realize that additional fields exist. Essentially, the tab order should follow the visual order.
If you have fields that are related or similar, consider grouping them together using field sets. For example, fields like "Full Name" and "Date of Birth" could be grouped together as "Personal Information." This type of form organization can help a screen reader user keep track of progress, and can provide the context that might be lost while filling out the form.
If certain form fields are required, the field should be labeled accordingly, and configured to alert the screen reader user. Commonly, required fields are noted as such with an asterisk, which will not be spoken by some screen readers. Asterisks (or similar visual indications) should still be used for sighted users, people with learning disabilities or people who speak English as a second language. Indicating that a field is required to a screen reader can be accomplished by adding ARIA required="true" and ARIA required="false" for optional fields. After submitting the form, user will need to be alerted to submission confirmation and any submission errors. We recommend including any error counts in the page title (after the user has submitted), so the user will immediately be informed that there are errors on the page. If a user submits a form with errors, the user should be brought to a submission page that indicates what the errors are, and provides an easy way to navigate to those errors.
Finally, the use of CAPTCHA is inaccessible and should not be used to validate submissions. WebAIM has a helpful summary of accessible alternatives (link is external) to CAPTCHA to keep forms free of spam submissions.
Using tables for page layout adds additional verbosity to screen reader users. Whenever a screen reader encounters a table, the user is informed that there is a table with "x" number of columns and rows, which distracts from the content. Also, the content may be read in an order that does not match the visual order of the page. Do not create the layout of a website using a table; instead, use CSS for presentation.
When a data table is necessary (i.e. you have a set of data that is best interpreted in a table format, such as a bank statement), use headers for rows and columns, which helps explain the relationships of cells. Complex tables may have several cells within the table that have a unique relationship to each other, and these should be identified by using the "scope" attribute in HTML. Table captions (HTML5) can be used to give additional information to users about how best to read and understand the table relationships.
Users with mobility disabilities, including repetitive stress injuries, may not be able to use a mouse or trackpad. These people are able to access content through the use of a keyboard by pressing the "tab" or "arrow" keys, or through the use of alternative input devices such as single-switch input or mouth stick. As a result, the tab order should match the visual order, so keyboard-only users are able to logically navigate through site content.
Long pages with lots of content should be broken up with anchor links (jump lists), allowing keyboard-only users to skip to relevant portions of the page without having to negotiate through other content. "Skip to main content" should be provided at the top of each page, so keyboard-only users won't have to tab through the page navigation in order to access the main content.
For pages with local menus and multiple levels and sub-items, the menus should be configured so that all menu items can be accessed with the keyboard. Do not use elements that only activate when a user hovers over items with a mouse, as keyboard-only or screen readers users will not be able to activate them.
ARIA (Accessible Rich Internet Applications) is an easy and powerful technical specification for ensuring your site structure is accessible. By assigning ARIA roles and landmarks to web elements, you enhance the ability of screen reader users to navigate and interact with your content. ARIA roles and landmarks can be easily added to your HTML, in the same way that you add classes to HTML in order to load attributes from CSS.
Examples of common ARIA usage include:
When content updates dynamically (i.e. without a page refresh), screen readers may not be aware. This includes screen overlays, lightboxes, in-page updates, popups, and modal dialogs. Keyboard-only users may be trapped in page overlays. Magnification software users might be zoomed in on the wrong section of the page.
These functions can easily be made accessible. Options include ARIA roles and alerts, as well as front-end development frameworks that specifically support accessibility.
Ensure that video players do not auto-play (non-consensual sound), and that the players can be used with a keyboard. Additionally, all videos must have options for closed captioning and transcripts for the hearing-impaired.
If your site contains a slideshow, make sure that each photo has alt text and can be navigated via the keyboard. If you are using any unique widgets (such as a calendar picker or drag-and-drops), be sure to test for accessibility.
If your page has multimedia, including audio tracks or video content, then provide captions or a transcript of any dialog. Audio also requires transcription. If you have create course content using a tool like Adobe Captivate or TechSmith Camtasia, you may already have available to you the means to place captions into your content – that is before it is uploaded into a video viewing platform.
A method should be provided to allow users to bypass lists of links that appear on every page within a site. When there is no blind equivalent for a “glance;” when blind users approach a new page for the first time, they generally review it in a linear fashion. If they need to hear lists of more than four repetitive links each time they get to a new page, this can get tremendously time consuming. To avoid this, “skip navigation” strategies can be used to bypass these links. There are multiple ways to do this; because there are some sighted users who can benefit from use of skip navigation, we recommend using a “Skip to Main Content” link at the beginning of the page that is either visible or becomes visible when it receives focus. This link has a corresponding anchor at the beginning of the content unique to that page. Other “Skip to…” links may be used as deemed appropriate, based on the page structure.
When a particular element on a page is receiving focus, browsers usually provide visual indicators such as a dotted-line box around a link or a cursor within a form field. If this does not happen automatically, page authors can use CSS or other means to provide a visual indication of the focus. In addition, authors should not deactivate users’ ability to see the visual indicator.