Joomla is a great Content Management System, used by millions of web masters and companies all over the world (even Sony Ericsson and MTV use them!). It has a large developers base and user community, which contribute to the improvement of the CMS by providing various extensions and bug fixes.
The strongest part of Joomla is its template engine. It’s very simple to use, and it’s powerful, allowing anyone with even basic designer skills to create very beautiful site templates. No other CMS looks as good as Joomla on the front end (although WordPress is slowly catching up).
But that templates engine is also its biggest drawback. The more beautiful the theme is, the more resources it uses, and the more powerful a server must be to run it well, especially when the site it’s installed on gets thousands of visitors per day. If you are on shared hosting, as most people are, you’ll find that it can actually make your account go over limit pretty quickly. But there are a few great solutions for this problem in the form of extensions. Here are some of the best (as voted on the Joomla web site):
IceSpeed. This should be the first extension you install. It’s free, and it does a lot to decrease not only the load on your hosting package’s resources, but also decrease the page load time by reducing the number of HTTP requests. It works by compressing all the CSS and JS files and also compressing all the responses that it sends to the client browser.
CssJsCompress. This extension works in similar way to the one above, but it is meant only for compressing the Javascript and CSS files, just as the name suggests. It has a couple of unique features, too, which may make it a better choice than IceSpeed: it can aggregate all of the CSS and JS files into one big file and have it cached on the client’s side, so the visitor only needs to load the page once and it will become much faster on all the subsequent loads.
JA Compress. JA Compress is another great extension, which does everything the above two ones do. IT is worth mentioning though, because it can also combine all the images of your template into one file (a zip archive for sending the response to the client browser, to be precise).
JCH Optimize. JCH Optimize is the fourth most popular extension that can help you speed up your Joomla site and reduce the load on your server’s resources. Aside from the usual CSS and JS aggregation and compression, JCH is well known for its great compatibility with most other plugins, so it will cause no problems if you have a lot of other extension installed.
Another way to significantly lower the load on a shared hosting package, no matter what CMS you’re using, is to use a Content Distribution Network. They are a relatively new technology available for the masses, and there are few public networks out there, but you can find them. The most popular right now are Coral CDN and MaxCDN, and the former is also absolutely free.
A CDN is comprised of thousands of servers connected together to form a network, which caches your pages and displays them to the visitors instead of your server, which means that you can get millions of page views per month while your shared hosting package is idling and you save hundreds of dollars!
There are other great plugins for Joomla that can significantly speed it up and reduce its load on a shared hosting package, but the above are the most popular and have recommended themselves as the best first choices. You should definitely try them out (the CDN trick, too)!