Using plugins
Generally it is a bad idea to make a page based entirely on plugins such as Flash or Java. Many pages use an entirely Flash interface, with multiple animations (mainly a marketing thing, because they think it's cool). Flash does offer some advantages, since when it is available, it works reliably cross browser. However, Flash has many limitations:
- Flash tries very hard to be accessible, but it is never as accessible as a normal HTML page. It cannot integrate well with accessibility software such as speech readers, and it gives no useful information about what is a heading or paragraph. Many Flash sites use scrolling sections of content - these scrolling sections do not hook into the normal scrolling mechanisms of the browser, meaning that they almost always demand the use of a mouse.
- Flash sites are almost entirely inaccessible to search engines. They cannot read them, index them, point users at sub pages within them, and not to be blunt about it, but if you never get onto a search engine, you might as well not have written the site at all.
- Flash sites rely on Flash (surprise). Not everyone has support for Flash. Some because it is usually used for distracting adverts, some because it is too slow, some because it takes far too much bandwidth to be comfortable on their connection, some because it is not available for the browser (or more often the device) that they are using, and some because they find it to difficult to use (because of disabilities etc.). They will not be able to see the site at all.
- Generally it does not cope very well with different display sizes, often scaling to become unreadable, where normal HTML could reformat itself.
- Displaying plugins in Internet Explorer requires ActiveX, which is disabled by many users or corporations because of security concerns associated with ActiveX.
If you want to use Flash or other plugins to display parts of your site, I suggest you do just that, use it to display only parts of the site, add decorations only, do not use it to display content or navigation. Leave that up to HTML, that is what it is there for. Try not to be so reliant on identical responses in all browsers, and instead, allow users to use what suits them.
Using it for cartoons, animations or games is ok, but if it is being used as part of a normal page, try not to make it too distracting or it will distract visitors from the main content - the reason they came to the site in the first place.
If you choose to make a splash page using Flash (although I fail to see why splash pages are needed - they serve no purpose except to say "I am not the page you came here to see"), provide a normal link to bypass the splash page.
Keep your flash movie small. In my personal opinion, if you have to display a progress bar to say when it has loaded, then it is too big. If it takes longer than 30 seconds to load on a standard modem, then it is too big.
Wherever you use Flash, or other plugins, make sure that you use the OBJECT tag, and use the TYPE attribute to specify the MIME type (not the classid) so that it works in the maximum number of browsers, then put alternative content inside the OBJECT tag's fallback. This is much more reliable than plugin detection scripts. You can do the same with the APPLET tag for Java. Generally it is a bad idea to use this to demand that they install Flash - you can be quite certain that they will have seen it before and if they do not have it yet, your site is unlikely to persuade them. Note that IE 7- does not display this content even if the plugin is not available. However, IE installs almost always have Flash and Java anyway, and if it is disabled, it is usually as a security precaution.
If you want to make an interactive page, try using JavaScript and DOM. It is able to take a normal accessible page and add interactivity to it, including animations. Generally it also loads faster as well.
If you want to use a streaming (audio/video) plugin, use a generic one. Preferably one that you can use on all operating systems. Flash is by far the most widely supported, and until enough browsers support the video and audio capabilities of HTML 5, it is probably thr best solution. Real Media (Real player format) is also available for most operating systems, but has become extremely unpopular. Do not rely on QuickTime or MS Media Player format. They may or may not be good, but again you are restricting your viewers.
If your site gives people documents in a different format, for example PDF, remember that not everyone can view them and some people cannot download them. They are confusing for disabled users, and deny the user's ability to use their normal browsing controls, as well as making it difficult or impossible to integrate with accessibility software. You should always include HTML alternatives whenever possible - they are using a Web browser, so give them a Web page. Almost no-one cares about printing or if the fonts look perfect - I know that is disheartening to a designer, but it is true. PDF should not be used to force your tastes onto your users.
Last modified: 15 February 2011