Adobe Flash is an application used for creating multimedia content, such as web applications, animations, desktop applications, and more. The Adobe Flash player was used on many websites during the late 1990s/early 2000s. While the Flash Player was quite popular, it also was prone to bugs and security vulnerabilities, consumed a lot of system resources, and was not equipped to support the ever-increasing wave of mobile devices. For these reasons and more, Adobe Flash officially went end-of-life in January 2021.
Avoid Flash on Mobile Web Pages (Deprecated)
What is Flash?
How to Avoid Flash on Mobile Webpages
Since the Flash Player is officially end-of-life and is not supported by any mobile devices, it should be avoided or not used at all at this point. HTML5 is a great substitute for any elements that require animation, or Flash-like functionality, and multimedia players like Lightspark, SWF File Player, and others.
Lighthouse is an open-source tool that is used to run an audit against your web pages and provides scores and suggestions for improving page performance, accessibility, SEO, and more.
PageSpeed Insights is a tool created by Google that reports on the performance of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved.