Adobe Flash or HTML5?

More as more sites are moving away from Adobe Flash; for good reason. Announced today, Slideshare, an online tool for sharing presentations, have completely rewritten their site to use HTML instead of Adobe Flash.

This has meant that their site is now functional not only without the Flash plugin, but also on iPhone, iPad, Android and any other mobile platform that supports HTML5. They’ve also claimed a 30% speed increase; and it is guaranteed to help with search engine optimisation.

So why ditch Adobe Flash? Since the beginning of ‘Flash’ (formerly Macromedia Flash), has been used to irritate and annoy web users through advertising and animation and frustrate programmers; while also used to delight gamers and help designers.

However, is has a few flaws; notably the site isn’t readable by a spider or search engine, and is only available on platforms that support Adobe Flash.

Adobe themselves claim a 99% installation on PCs; much higher than say Java or Quicktime – we’d love to question these figures, and it is simply not available on mobile platforms.

What are the issues?

  • Flash is a proprietary product; the code for how it works is not available, and Adobe do often change their code and update it. It’s also been famed for causing browser memory issues, so much so that Apple declined to have support on the iPhone and iPad.
  • Not only that, but Flash has been a primary target for slipping malware and viruses, especially via social networks such as Facebook.
  • Using Flash tends to break conventions associated with normal HTML pages. Selecting text, scrolling, forms and right clicking are not part of the browser.
  • Flash player has to be able to animate on top of video renderings, which makes hardware accelerated video rendering more complex than a purpose-built multimedia player.
  • Flash is also often blocked in some browsers; and will only play after being clicked.


So what are the alternatives? Naturally HTML5 can solve a great number of these issues, while also preserving your site for web spiders and search engines. However, HTML5 does have issues with video.

Adobe seem to be creeping out of the ‘experience’ part of HTML, and is almost always only used for video streaming and games. The reasons are simple, gaming in HTML5 can be complex, and Adobe has been written almost solely for this purpose.

As for video; there are few options. Due to various disagreements, there is no single standard for HTML5 video – unlike for Flash Streaming (which uses FLV).

The current HTML5 draft specification does not specify which video formats browsers should support. Web browser are free to support any video formats they feel are appropriate. Originally Ogg Theora was recommended since it is not patented and wouldn’t require licencing.

Most browsers will support Ogg Theora, but Safari and Internet Explorer require manual installation of the codec to support playback. Other alternatives such as H.264 are supported in these browsers, but aren’t available at all in others.

A quick guide, from Wikipedia is below; it’s easy to see why so many sites still use Adobe Flash for streaming.

BrowserFormats supported by different web browsers
Ogg TheoraH.264VP8 (WebM)Others
Internet ExplorerManual install9.0Manual installNo
Mozilla Firefox3.5No4.0No
Google Chrome3.0No (removed at 11)6.0No
SafariManual install3.1Manual installManual install
Konqueror4.4Manual installYesManual install
Epiphany2.28Manual installYesManual install