Flash
Multimedia Technology
Good reading - Five Ways Using Flash Can Damage Your Site (opens in new tab/win) (devshed, 2010-04-21)
(The five ways are A Flash Intro (1), Designing an All-Flash Site (2), Using Flash Headers (3), Using Flash on Your Menus or Side Bars (4), and Embedding Too Many Flash Games onto Your Site (5).)
| Browser Test | Static Picture How it would look like when visitor have Flash: |
Static Picture How it would look like when visitor have Flash disabled: |
Flash Media Can you see it? |
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|---|---|---|---|---|
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Considerations
- Availability
- Flash is not available on all platforms (e.g. not iPhones and iPads - Apple's main argument is security concerns). And even when available (installed on visitor's computer), lots of people select to disable Flash.
- Usability
- Unfortunately, many developers uses Flash in ways that are not adding to the usability of web sites. For instance, implementing navigation functionality using Flash is not very good (see example below). (Much better alternative is using CSS and JavaScript.)
- Flash is also often viewed as something annoying and intrusive (due to many news sites using Flash for ads). Again, why being disabled/never installed.
- Performance
- As commented on below (Mr. Nyman), performance issues may be more due to bad development/implementation than the technology itself. Unfortunately, for visitors of your site site why he/she has performance issues doesn't matter, and they select to disable/never install.
- Security
- Flash has a long history of security issues and many experts in the information security (InfoSec) community straigh-out recommend never touch or consider any Flash on your computer. There are also companies and other organizations that disable Flash and these will thus not be able to see your content.
Extract from wikipedia.org/wiki/Adobe_Flash
"Flash's poor security record[54] has caused several security experts to recommend to not install Flash or to block it[55]. The US-CERT recommends to block Flash using NoScript[56]. Charlie Miller recommended "not to install Flash"[57] at the computer security conference CanSecWest. As of March 27, 2010, The Flash Player has 75 CVE entries[58], 34 of which have been ranked with a high severity (leading to arbitrary code execution), and 40 ranked medium. In February 2010, Adobe officially apologized[59] for not fixing a known vulnerability for over 1 year."
- Flash has a long history of security issues and many experts in the information security (InfoSec) community straigh-out recommend never touch or consider any Flash on your computer. There are also companies and other organizations that disable Flash and these will thus not be able to see your content.
- Discoverability (for web site owners, promoters, marketing) - remember that Flash-based content is not discoverable/indexed by major search engines like Google and Yahoo. For this reason, as well as for for other reasons above (availability, usabilty, performance, security), you should always create fall-back solutions for any Flash-based media or functionality.
Pros and Cons
http://www.google.com/search?q=adobe+flash+pros+and+cons
From http://robertnyman.com/2009/03/02/adobe-flash-pros-and-cons/
The good parts
Flash can offer a richer experience in regards to animations, transitions and music handling. It has been there from day one to complement HTML where that isn’t sufficient in offering a more full-fledged media experience.
Being a controlled runtime, it can offer exactly the same content through web browsers and platforms, without any additional code. It is probably the most spread web browser plug-in in the world.
Especially as of the latest years, it has also become the de facto way of showing videos in web sites (YouTube, Vimeo etc) because of its compressing and packaging abilities, and is a great way around common video codec issues, showing something completely full-screen and other features.
When it comes to other presentational means, Flash can help you use any font you want, and is naturally a nice way to offer games.
The bad parts
What seems to be the biggest annoyance for people is poor performance and lots of unwanted animations and such. When it comes to performance, while it can be controlled by Flash developers, they seldom seem to do it and/or they can’t control the total number of Flash movies in the same page.
For instance, go to most major newspaper web sites and no matter how good a computer you have, it will be brought down on its knees. I’ve spoken to Adobe representatives about this, but they claim there’s no performance problem whatsoever in Flash and that it’s all the developers’ doings.
One factor which worries web site owners who are focused on SEO is about lost search engine ranking placement for content within the Flash movie. The correct way to use a Flash movie in a web page is to have an alternate HTML fallback in the HTML code, both for SEO and accessibility reasons, and to use JavaScript to dynamically insert your Flash movie.
Sadly, most developers seem to disregard accessibility, and when it comes to SEO the answer is usually: “Google are working on indexing Flash movies, so the problem will soon be gone”. What they don’t seem to realize, however, is that no matter if Google and and other search engines manage to index the content, if it isn’t built up with proper code and in a good semantic manner, it’s impossible to index it properly, give the correct weight to certain terms etc.
Another of the problems with Flash is that it is included in the web browser as a complete stand-alone runtime, meaning it would work just the same in a stand-alone Flash player. The effect of this is that if you focus the Flash movie, all web browser keyboard shortcuts and focus is lost, and you need to click outside of the Flash area to re-focus.
Additionally, I’m not sure people do their homework, but since Flash seem to be widely disliked (most likely to a complete and obtrusive overusage in advertisement context), people do turn it off, refuse to update their Flash player or install extensions such as Flashblock (almost 6 million downloads, 51 000 a week – definitely not something to sneer at).
Should you use Flash?
Sure, if you think it can bring extra value to your end users. But unless you’re building some artist/band web site, then (and maybe not even then) is it an option to build a web site only with Flash. I would rather recommend to use it for something more like a feature in a web site’s start page, to heighten the experience, but at the same time make sure that it has a proper fallback, especially if if contains any important information.
Take the above shortcomings into consideration, and if you use it, use it sparingly and above all, respect your visitors.
A Bad Example
A really "good" example of the worst kind of using Flash.
- Navigation is implemented using Flash - unusable for visitors, can't navigate.
- Significant part of page is using Flash - wasting valuable screen real estate.
- No fall-back solution for visitors that doesn't have Flash installed or enabled.
1a) Without Flash - as it looks like when people have turned off/disabled Flash:
1b) When / If Enabling Flash:
(The above are static screen shots from http://magnetek.com/ as retrieved 2010-04-22)
2) The following is a real-time included page from the same site - how it actually looks in your web browser just now:
Disable Flash
If you want to get rid of annoying ads, and/or improve performance and security:
- How to disable Flash in
- Add-ons:
- Flashblock - https://addons.mozilla.org/en-US/firefox/addon/433, flashblock.mozdev.org/ (one we're using)
Developing Flash Content
As with any development for the Internet and web browsers, the following should be considered:
- Visitors' - intended target groups' - operating system(s), browser(s), availability of plug-ins (can't do very much about them disabling, aside coding fall-back solutions).
- I.e. always plan with fall-back solution for Flash-based content.
- What versions of available software - (e.g.) version of Flash. Even if Flash is around version 10 (Apr 2010), many people doesn't have the latest and greatest and may be as far back as Flash 3,4, or 5... Must be considered when programming and selecting specific features of Flash.
A few found resources:
- How to detect the presence of the Flash Player
- A comprehensive list of supported Adobe Flash features, specific to each browser
References
- en.wikipedia.org/wiki/Adobe_Flash
- adobe.com/products/flash/
- google.com/search?q=security+issues+with+flash
- sans.org/top-cyber-security-risks/ - mutiple Flash-related problems among the top-listed problems (Apr 2010).