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HTML5 vs. Flash – What You Need to Know

It’s been five years since the announcement of HTML5, and yet the HTML5 vs. Flash debate continues to rage on among developers. Everywhere you look, from newspapers to magazines to the Internet, you’re swamped with articles about these technologies, often offering conflicting advice about which is the better solution. With all the noise on this subject circling in the technology stratosphere, how do you decide which one is best for you?


Released in 1996, Flash is a multimedia platform originally developed by Macromedia and later acquired by Adobe. By 2000, it had become the de facto standard for video playback, animated banners, and interactive multimedia web pages. Flash essentially became the standard tool in a non-standard web of multi-platform browsers.

HTML was developed by the World Wide Web Consortium (W3C), a group whose main purpose is “to guide the World Wide Web to its full potential by creating protocols and guidelines that ensure the growth of the web in [the] future”. The last HTML specifications focused on future developments were XHTML 2.0 and HTML 4.01, but neither had been updated since 2000. With developers eager for a single markup language that included detailed processing models to encourage more interoperable implementations, HTML5 was born.

The initial HTML5 specification was officially announced in 2007, but it did not become a major topic of discussion until April 2010. It was at that time that then-CEO of Apple, Steve Jobs, issued a public letter titled “Thoughts on Flash” where he concludes that “[Adobe] Flash is no longer necessary to watch video or consume any kind of web content” and that “new open standards created in the mobile era, such as HTML5, will win.”

The Debate

Proponents of Flash argue that, with over 1 billion users worldwide, Flash isn’t going away any time soon. The numbers, according to Adobe, support them:

  • 70% of web-based games are built using Flash, including 24 of the top 25 Facebook games
  • 75% of web videos are viewed using Flash (YouTube was solely Flash until adding HTML5 video playback in 2011)
  • 98% of enterprises rely on the Flash Player and more than 3 million developers use Flash technology
  • 85% of the most-visited websites use Flash in one form or other

Flash fans also argue that, with 99% of browsers supporting the technology, they have a much larger audience reach. In addition, since all of the Flash “code” is compiled into a SWF file, someone looking to view the source would have to crack two levels of encryption to get what they need, a fact that many developers appreciate. Plus, because it’s owned by a single company, Adobe has complete control of the technology’s innovation rate.

HTML5 advocates argue that several of the things Flash fans see as pros are actually major drawbacks. Because the technology is driven by one company, Adobe and Adobe alone determines the future direction of Flash. The specification for HTML is developed by an open standards development consortium that relies on feedback, allowing developers to shape the future growth of HTML.

Developers who prefer HTML also argue that because Flash code is compiled, there is no way for a search engine to properly spider the content. That means all the great content in your flash banner, animation, or video adds nothing to your site’s search engine optimization (SEO). HTML content is read as plain text by a spider and, when properly formatted, can provide a big boost to your site’s search engine placement.

Finally, while Flash can boast more current browser support, HTML5 is rapidly gaining in the adoption of its respective features. Almost all modern browsers include support for HTML5, as do most browsers in tablets and mobile phones (many of which are not capable of running Flash at all).

Our HTML5 vs Flash [infographic] illustrates the debate.

Is Flash Dying?

While Flash has definitely maintained a large market penetration that probably won’t evaporate completely, it would be hard to argue that it’s not ceding ground to other technologies, namely HTML5. In accordance with Steve Jobs’ letter, Apple products such as the iPad and iPhone do not offer built-in Flash support (although there are add-ons that will allow it to work). Assuming you have accepted their trial, YouTube now uses Flash only as a fallback; if your browser supports HTML5, YouTube uses the newer HTML5 video playback features. YouTube very much sees HTML5 as the future, made clear on their blog when they said: “We are very excited about HTML5 as an open standard and want to be part of moving HTML5 forward on the web.”

If the decisions made by those big players aren’t enough to convince you a shift is happening, consider this: Adobe themselves have announced they “will no longer adapt Flash Player for mobile devices to new browser, OS version or device configurations.”

OK, HTML5 it is!

So now you’re sold and ready to switch to HTML5, right? You didn’t really think it would be that easy, did you? There are several key points that you need to remember concerning HTML5:

  • HTML5 does not officially exist yet. It’s currently a specification in working draft, but is not scheduled for publication until 2014. Also, it’s expected to continue with updates and revisions through at least 2022!
  • While HTML5 is rapidly gaining support, there are still older browsers and platforms that do not currently support it. Most developers would rather ignore this, but you shouldn’t, not when 6% of the world is still using IE 6 (as of July 2012).
  • The new elements and features in HTML5 are great starting points and will continue to mature as the specification advances. However, some of these elements, including the new tag, are not currently capable of the advanced features such as streaming, captions, and interactive playback that Flash and Silverlight support.

If you’re ready to start using the latest HTML5 technology, it’s important to use shims (shivs or whatever terminology you prefer) to allow backwards-compatibility with older browsers. Tools such as Modernizr allow you to detect what technologies are available in the users’ browser, so you can determine which features you’ll be able to employ.

While continuing to fully support Flash environments with such products as the PrizmDoc , Accusoft is committed to taking full advantage of HTML5’s capabilities as the specification emerges. PrizmDoc also supports HTML5 browsers, and our ImageGear for .NET toolkit for building custom imaging applications incorporates HTML5 functionality. ImageGear for .NET customers can now create true zero footprint web-based and mobile applications that use ASP.NET HTML5 controls to display images and thumbnails of over 100 different file formats, including Microsoft Office formats and PDF files. You can download free evaluations of PrizmDoc or ImageGear to see the HTML5 support up close.

The web continues to evolve, and with newer and more powerful technology options, it’s certainly an exciting time to be a part of it all. As with any other business decision, you have to consider your target audience before you can make the right technology choice. While HTML5 is gaining a tremendous amount of support, Flash is far from dead and still remains a viable choice for the right business applications. If you do decide to forge ahead with the latest technology, always incorporate shims so you can maintain backwards compatibility. Here’s wishing you success.

About the Author

Chris Casale manages web development at Accusoft. He holds a Computer Science degree from the University of Central Florida, where he was inducted into Upsilon Pi Epsilon, the international honor society for the computing and information disciplines.