All websites and apps must conform to the international Web Content Accessibility Guidelines (WCAG 2.0) standards which are guided by four main principles known as POUR.
Perceiveable - This is about how the website can be perceived, in other words, it’s whether elements and content is identifiable to the user via our senses. For most users, it’s visual but it can also relate to sound and touch. One example could be that a website requires alt text for images to help the user understand the content better.
Operable - Users need to be able to use interactive elements like buttons and controls successfully. A lot of visually impaired people can be quite reliant on keyboards instead of the mouse and the website must be able to accommodate this need. If you have text on carousels, the users need to be able to have enough time to read it - it can be little things like that that really make a difference.
Understandable - Users need to fundamentally understand your website. If things are phrased oddly or there’s an abundance of acronyms without definitions, it can be quite hard for users to understand the content.
Robust - This isn’t to do with how strong a website is but is more about the ability for users to be able to use your website with whatever device and in whatever browser they want to use. If your website is reliant on a specific browser version in order for all elements to work and all content to be displayed, then this could fail the accessibility guidelines.
Alt Text for Images - Adding alt text to images can help those with screenreaders better understand the content. It also helps Google Bots understand the content better too.
Use Headings - Headings not only help Google bots understand your content but they also help users understand the structure of your page and website too.
Use labels on Forms - Adding labels to form fields will help the user understand what needs to be inputted into each of them. Adding an asterisk will also help the user understand which of the fields are mandatory. Review padding and whitespace - Elements and text that are all bunched together can be very difficult to read, so use padding and white space wisely.
Transcribe your videos - Including transcripts for videos can help both search engines and users better understand your video content.
Simplify your navigation - Keep top navigation menus simple and uncluttered. It can be tempting to throw every single thing into the navigation but your user will need to find what they need quickly and easily. Keep the navigation menu clean and make sure that the user is able to navigate easily into sub categories without a problem.
Make it logical - This also relates to the point above regarding headings and structure and UX (user experience).Think about how your user will need to read the page - they don’t want to have to jump up and down the page like a kid on a pogo stick to find what they are looking for. Check the flow of your content and order your information with care.