Flash (or Adobe Flash) is a web technology for displaying interactive animation, video and applications on the web. It is one of the most ubiquitous technologies used on the web.
- Streaming video. YouTube famously uses Flash to provide streaming video, although has since begun to move to HTML5.
- Animation, such as banner advertising.
- Online games or interactive applications.
Note that Flash is not the only means of providing these features on a website, but it is one of the most common.
All Apple iOS based devices (iPhones, iPads and iPods) do not support Flash; Apple has made it clear that they do not intend to add support in future, advocating HTML 5 instead. More recent Mac computers ship without Flash installed. Generally support for Flash across all mobile devices is currently patchy.
Used incorrectly Flash can significantly hinder effective Search Engine Optimization and Accessibility. The effect is especially pronounced on sites which are built exclusively in Flash – these sites are inaccessible to large groups of users and search engines, and exhibit other well documented problems.
Sitebeam tests for the appropriate use of Flash with the Flash test.