How do you define which browsers are 'optimised' versus 'usable'?

These are two terms that all our clients get to know when building a website. Every browser is different and therefore displays websites slightly differently. Most modern browsers display web pages near-identically, some of the older ones display quite differently.

We use these two terms to define the browsers that are going to display a fully functioning website (optimised) and the browsers that will display a website that does what it needs to do, but might be missing some bells and whistles (usable). Prior to 12 months ago, this pretty much meant how closely the web page is to the design created in Photoshop.

Today, in the age of responsive design, this means something new.

Responsive design can be pretty taxing. The maths and transitions needed for expanding and collapsing correctly requires a fairly competent browser. It’s easy to get in a long winded battle trying to make Internet Explorer 7 display a responsive website, but is this necessary?

It’s easy to put every browser in the ‘optimised’ list, because you’ve looked at your Google Analytics and discovered that people are still viewing your website on Internet Explorer 6. Is the effort to get these browsers over the line worth the 300 visitors a month though?

If it makes the decision easier, it’s often forgotten that people running Internet Explorer 6 and 7 are exceedingly unlikely to be viewing your website on anything other than a desktop or laptop.

Getting a realistic balance of optimised vs. usable saves more budget for the optimised user and doesn’t waste time with getting Internet Explorer 7 users (that are updating everyday) across the line.