How to install Firefox 3 and Opera 9.51 with other versions

17 July, 2008

OK, so just a quick, simple article this time. How to install Firefox 3, or Opera 9.51, or pretty much any browser that is not Internet Explorer, while still keeping working copies of the previous versions.

First off: why do we want to do this? Well, for testing of course! It is important to test our web content in a variety of browsers to see that it displays and behaves the way we want. And when a new browser comes along, it is crucial to have your site display properly in that new browser. However, what about the old browser? We still need to test in that as well to allow for our users that have not upgraded yet. And so we need to install multiple versions of the same browser.

Now, this is nothing to be scared of as the whole process is very easy and straight-forward. The process is essentially the same for both browsers (or any browser other an IE) so we can apply the same instructions to both.

First, you will need to create a new folder to install the new version of the browser to. We created a directory in the original location: C:/Program Files/Mozilla Firefox. We called this directory Firefox3. So now we have C:/Program Files/Mozilla Firefox/Firefox3. (For Opera, find C:/Program Files/Opera and create a new directory there.)

This is where we will install Firefox 3 to.

So now go ahead and run the install file you downloaded. After clicking through the Terms and Conditions screens, select Custom - this gives us the option of where to install Firefox 3. Select the new directory you created and click Next. On the following screen, do not elect to create icons anywhere. Past experience has shown this can overwrite the Firefox 2 icons and shortcuts we are going to want later. Click Next and Install, and watch it go.

Once it has completed installing we are going to want to create our own shortcut. Navigate back to the directory where you installed it to and find the Firefox EXE, firefox.exe. Create a shortcut to this file where-ever you think you need one.

And that is all there is to it. Two (or more) working versions of the same browser. Now you can continue to develop content and test it in multiple browsers to ensure it all works well.

As a parting note, we think it is worth mentioning that fcOnTheWeb only tests backward one version. Users of browsers like Firefox and Opera are "early adopters" of technology so it is safe to assume the number of users stuck on an older version of the browser are few and far between. This is not the case with Internet Explorer though, as it is the default browser shipped with Windows. Many users are still using older versions as they have not upgraded, or cannot upgrade, and so it is important to test with a range of versions there. But that is an explanation for another article.

Mozilla has a more in-depth tutorial of how to install Firefox 3 with previous Firefox versions while maintaining separate profiles, etc., however we haven't covered that as it's not necessary when using Firefox for testing purposes. The tutorial is available here: http://support.mozilla.com/en-US/kb/Running+different+versions+of+Firefox+at+the+same+time

*NEW CONTENT* - 31 July, 2008

It appears that if trying to open both versions of Firefox at once the second one will be the same version as the first one launched. Just something to be aware of. This does not appear to affect Opera however.

ferrari_chris