Poor color contrast. People with limited vision or color blindness cannot read text if there is not enough contrast between the text and background (for example, light gray text on a light-colored background).

Use of color alone to give information. People who are color-blind may not have access to information when that information is conveyed using only color cues because they cannot distinguish certain colors from others. Also, screen readers do not tell the user the color of text on a screen, so a person who is blind would not be able to know that color is meant to convey certain information (for example, using red text alone to show which fields are required on a form).

Lack of text alternatives (“alt text”) on images. People who are blind will not be able to understand the content and purpose of images, such as pictures, illustrations, and charts, when no text alternative is provided. Text alternatives convey the purpose of an image, including pictures, illustrations, charts, etc.

No captions on videos. People with hearing disabilities may not be able to understand information communicated in a video if the video does not have captions.

Inaccessible online forms. People with disabilities may not be able to fill out, understand, and accurately submit forms without things such as Labels that screen readers can convey to their users (such as text that reads “credit card number” where that number should be entered), clear instructions and error indicators (such as alerts telling the user a form field is missing or incorrect).

Mouse-only navigation (lack of keyboard navigation). People with disabilities who cannot use a mouse or trackpad will not be able to access web content if they cannot navigate a website using a keyboard.