Which Browsers Should a Website Support?

Ensuring that a website looks and functions the same regardless of the web browser that a visitor uses is a big part of a web developers job. ‘Which browsers should a website support’ is a question that comes up often and the simple answer is that there is no definitive answer.

The answer could be different depending on the type of site and the target audience. For example, a big company selling products around the world will probably want their website to support older browsers than a blog about the latest technology.

It is also a matter of personal preference. I tend to stick to a few general rules.

The browsers

The first thing to take into consideration is the proportion of people using each web browser. The table below shows the worldwide usage share of web browsers as of March 2011.

This can then be compared to the statistics for this site, shown in the table below. The main difference between worldwide browser usage and the browser usage for visitors to this site (who are primarily UK-based) is the higher share that Firefox has. This will be, in part, due to the dominance that Internet Explorer has in areas of the world, such as China, where this site does not receive many visitors from.

What about the version of the browser?

It’s pretty obvious that a website should support all the major browsers, that is to say Internet Explorer, Firefox, Chrome, Safari and Opera, but since there are multiple versions of each, the tables above only tell half the story.

Let’s look closer at visitors to this website who use Internet Explorer. The table below shows which version they were using when they visited.

The vast majority of visitors using Internet Explorer 8 is to be expected since the latest version, IE9, was only released a few weeks ago. What is most interesting about these statistics is the number of visitors still using IE6 and IE7, both of which are way out of date and, in the case of IE6, almost 10 years old.

With so many visitors still using IE6, this causes a headache for web developers since IE6 does not fully or properly support CSS2, making it hard to ensure compatibility without degrading the experience for users of more modern browsers.

What about the operating system?

Something else to take into account, particularly with the rise in mobile web browsing, is the operating system that visitors use.

The operating systems used by visitors to this website are shown in the table below.

The most significant information to take from these statistics is the high percentage of visitors using iPhones. Since the iPhone OS doesn’t support Flash, any website with Flash elements should have alternatives in place to ensure the experience of visitors using iPhones is not degraded and the site remains usable.

Which browsers to test?

As already mentioned there’s no definitive answer. As a general rule I make sure my websites support (as far as possible in the case of IE6) the following browsers.

• Firefox 3.x – Versions 3.0, 3.5 and 3.6 fall into this group. It’s unlikely that any differences would exist between these versions, so I generally test against one of them.
• Firefox 4.0 – The latest version of Firefox, released in March 2011. Likely to take a large share of users away from Firefox 3.x.
• Internet Explorer 9 – The latest version of IE. Likely to take a large share of users away from earlier versions of IE.
• Internet Explorer 8 – The most commonly used version of IE at present.
• Internet Explorer 7 – Old, outdated, but still surprisingly widely used. Can occasionally prove to be awkward to code for, but generally a lot less problematic than…
• Internet Explorer 6 – As awful as IE6 is, I still test and try as far as possible to make websites compatible, but don’t spend too much time worrying about it. With the advances in web development since IE6 was released (almost 10 years ago !), it’s often impossible to achieve the same results as is possible in more modern browsers.
• Chrome – Google’s own browser has a big enough share of the market to warrant inclusion. I test the latest full release.
• Safari – Apple’s browser comes installed as the default browser on all Apple desktops and laptops. It is also available for Windows.
• Safari (iPhone) – The mobile version of Apple’s browser does not support Flash. It’s (usually) important to ensure websites translate well into mobile browsers.
• Opera – The least widely used browser that I support, Opera still has a user base that is large enough to take into consideration.

Summary

The list of browsers above may seem like a lot, but, as long as websites are built with well-written and valid code, I find the more modern browsers are pretty simple to support. The vast majority of problems are likely to come from older versions of Internet Explorer, but most of these have been tackled thousands of times already and are relatively well documented online.