HTML and CSS Reference
the site visitors rely on older browsers, you won't be able to utilize the most advanced technologies.
If at all possible, it's important to review website statistics to get a better picture of the site's audi-
ence. Key aspects include:
Take note of which browsers are used by the majority of site visitors as well as
which are hardly used. Identifying the most-often used browser will help you establish a
baseline for HTML5 support, and discovering the least-used allows you to avoid features
that are supported by only those browsers.
Understanding which versions of your most-used browsers are visiting the
site is key. It doesn't matter if Internet Explorer 9 supports a feature if 75 percent of your
users depend on version 6.
the language without careful consideration.
Although not critical to HTML5-related decisions, figuring out how your
site is being viewed — whether it's on resolutions of 800 x 600 or 1280 x 768, for example —
will help you determine the optimum layout for your site.
In addition to examining the site statistics for this information over a set time period, it's a good
idea to keep an eye on trends. For example, say that during the past six months, an average of 8 per-
cent of users visited the site with Internet Explorer 6. Though the amount is relatively small, it is not
insignificant. However, if you then examine the previous 6-month period and find that the percent-
age of visitors relying on that browser was 12 percent, you can expect that older browser usage will
continue to decline and bolster your case for more advanced HTML5 functionality.
wHaT works now
Want some good news? A great deal of the most desired HTML5 features are supported in the
majority of the key browsers. Moreover, because competition is so fierce between the browser teams,
updates are being released more frequently and the trend is to include more HTML5 functionality
with each new version.
Currently, of the five major browsers — Internet Explorer, Firefox, Safari, Opera, and Chrome — all
but one support about 90 percent of HTML5 functionality. Unfortunately, the current version of
Internet Explorer, which retains the lion's share of market, supports only about 75 percent.
Specifically, the HTML5 media elements — <audio> , <video> , and <canvas> — are among the best
supported with solid implementations in Firefox, Safari, Opera, and Chrome. Again, Internet Explorer
is lagging behind with the current version, but version 9 is already in beta testing and expected to be
released in less than a year. Moreover, as discussed in Lesson 25, methods are already in place that
allow such content to be displayed should the tags not be supported in a given browser.
Interestingly enough, one of HTML5's most advanced features, web storage, already enjoys uni-
versal support among current browsers. This new ability allows website developers to store larger
amounts of data on the user's system than was previously possible.