Each website has an optimal design that matches thematic types, requirements, and visitors. For example, websites that offer e-cards definitely need to catch the eyes of visitors, use images, animations, and interactivity, while sites dedicated to science, teaching or investigations may not require one of those who show information and its contents.
The number of animations or interactivity will certainly affect the accessibility of web pages given that the technology used to provide this type of content is usually not supported by a user agent or many times not designed for disabled people. To consider how many people you can leave behind me will base my study of this site’s statistics (HTMLQuick.com) which are fully accessible and provide a lot of textual information.
To see some round numbers I would say that if the site content will be fully based on flash or Javascript we will lose from 1.77% to 4.55% of visits only due to lack of technology, which can be a large number of visitors if the site is successful. But let’s pay attention to some considerations based on the most popular and problematic technology available.
Flash
Flash is a great way to build animation and interactivity but can also be a big accessibility problem. Make a website completely in flash can issue 2.78% of visitors and make the site completely empty for search engines, which might be your main discomfort.
Many sites will see flash as a major requirement while others can only use it for animation or will not use it at all.
– If your site doesn’t need it, then try use it only for animation or provide a rich alternative text.
– Avoid building menus in flash, because the user agent does not support it will not be able to follow their link.
– Export SWF files use the lowest version. Only 69.2% of visitors who use the latest version. The remaining 29.03% must download before playing a movie.
– Try to make the size of the film as little as possible so that people don’t get bored waiting for the page loaded. There are still 11.83% of visitors using dial-up connections.
Javascript.
JavaScript has a similar problem for flash. Many users will not support it, including search engine robots. 1.77% of visitors will not be able to see information written in Javascript or follow the link.
– If possible use only for interactivity and functionality that is not needed.
– If not, give alternative static content in the tag “noscript”.
– Don’t make it need to take part in the link. Use the “Location.Href” command as a “OnClick” event in a static link (“a” tag).
Frame.
A good frame, but it must be avoided definitively. While most users agents support frames, search engines, and blind people, can be very confused when trying to connect the information contained in various frameset pages.
Images
Image, even when it is not accessible, is a better alternative for Flash animation.
– Always prefer to use images instead of flash animation.
– Small size size to reduce page open time.
– Always give the most appropriate alternative texts that describe the purpose of the image.
Some ways to generally avoid the use of technology that conflict is to choose the type of information that is more general or more supported. One of the best alternatives to set the display of websites is CSS. CSS is specifically designed to set the presentation attributes. Use it instead of the table to set the layout.
