Alt text (1.1.1): All images and non-text content needs alt text (there are exceptions)
Video & Audio alternatives (1.2.1): All video-only and audio-only content has a text transcript. Transcripts are clearly labeled and linked below the media.
Audio description (1.2.3): For any video, add an alternative video that includes an audio description of information not presented in the original video’s soundtrack (exceptions) or include a text.
Audio description (1.2.5): An audio description is optional under 1.2.3 level A but not in 1.2.5 AA.
Presentation
Website structure (1.3.1): Use proper markup techniques to structure your website’s content (e.g. use correct heading tags and HTML for ordered and unordered lists)
Meaningful order (1.3.2): Present content in a meaningful order and sequence so that it reads properly.
Sensory characteristics (1.3.3): When providing detailed instructions, make it so they aren’t reliant on a single sensory ability.
2.1Orientation (1.3.4): Style your website so that it does not lock on or require a single display mode
2.1Input (1.3.5): Make it so forms can autocomplete information for users.
2.1Reflow (1.4.10): Ensure someone can zoom in on your website without requiring scrolling or without causing poor experience.
2.1Non-text contrast (1.4.11): All meaningful non-text content on your website should have sufficient contrast with the background.
2.1Text spacing (1.4.12): Make sure your text spacing is able to be adjusted without causing a poor experience.
2.1Content on hover or focus (1.4.13): Make it so any additional content (e.g. pop-ups, submenus) can be dismissed or remain visible if the user desires.
User Control
Keyboard only (2.1.1): All content and functions on a website must be accessible by keyboard only (i.e. no mouse).
No keyboard trap (2.1.2): Keyboard-only users must never get stuck on any part of the website; they must be able to navigate forwards and backwards.
2.1Keyboard shortcuts (2.1.4): If you have a keyboard shortcut, make sure a user can either 1) turn it off, 2) there’s a way to add another key in the shortcut, and/or 3) have the shortcut only active while focusing on a specific component.
Adjustable time (2.2.1): If there any time limits on a website, users have the ability to turn it off, adjust it, extend it.
Pause, stop, hide (2.2.2): If there is content that blinks, scrolls, moves, users must have the ability to pause, stop, or hide it.
Three flashes or below (2.3.1): Web pages do not contain anything that flashes more than three times in any one second period.
Skip navigation link (2.4.1): A “Skip to Content” or “Skip Navigation” link allows users to bypass the heading and go straight to the main content.
Understandable
Page titles (2.4.2): Each page of a website needs to have a unique and descriptive page title.
Focus order (2.4.3): Users must be able to navigate through a website in a logical sequential order that preserves meaning.
Link anchor text (2.4.4): The purpose of each link should be clear based on its anchor text (e.g. don’t use “click here”)
Multiple ways (2.4.5): There are multiple ways to access different pages/information on a website (e.g. search bar, nav menus, sitemap, breadcrumbs, helpful links after content).
Focus indicator (2.4.7): Any “user interface control” that receives focus from a keyboard user should indicate that focus on the current selected element (e.g. add a visible border around a text link).
2.1Pointer gestures (2.5.1): Provide simple alternatives (e.g. single tap vs. swipe) to potentially complex finger motions on touch screens.
2.1Pointer cancellation (2.5.2): Provide a way to cancel the trigger when you click down on a mouse or press down/touch with your finger.
2.1Label in Name (2.5.3): Make sure any programmatic labels you make are aligned with the corresponding visual text.
2.1Motion Actuation (2.5.4): For any functions that are activated by motion, provide a simpler, alternative means of action. Also, give users the option to turn off motion activation.
Language changes (3.1.2): Indicate any language changes for an entire page or within the content.
Predictability
No focus change (3.2.1): Nothing changes merely because an item receives focus; a user must actively choose to activate an item (e.g. hit enter to submit) before a change takes place.
No input change (3.2.2): Nothing changes just because information is inputted into a field (e.g. form doesn’t auto submit once all fields are filled out).
Consistent navigation (3.2.3): Keep navigation layout consistent throughout all pages of the website (e.g. same links in the same order).
Consistent identification (3.2.4): Components that have the same function within a website are identified consistently (but not necessarily identically) (e.g. two check marks can indicate two different things as long as their function is different — one indicates “approved” on one page but “included” on another).
Form labels and instructions (3.3.2): Programmatically label all form or input fields so that a user knows what input and what format is expected.
Error suggestions (3.3.3): If an input error is automatically detected, then suggestions for correcting the error should be provided.
Error prevention on important forms (3.3.4): For pages that create legal commitments or financial transactions or any other important data submissions, one of the following is true: 1) submissions are reversible, 2) the user has an opportunity to correct errors, and 3) confirmation is available that allows an opportunity to review and correct before submission.
Parsing (4.1.1): Make sure HTML code is clean and free of errors, particularly missing bracket closes. Also, make sure all HTML elements are properly nested.
Name, role, value (4.1.2): For all user interface components (including forms, links, components generated by scripts), the name, role, and value should all be able to be programmatically determined; make sure components are compatible with assistive technology.
2.1Status Messages (4.1.3): When a status message appears, it should be coded with role or properties so that people using assistive technologies (e.g. screen readers) are alerted without losing focus.