There are many ways to speed up loading a web page. Of course, I assume that you use a fast web hosting service. First of all, remove anything You or Your Client don’t really need – especially from the first page.
Reduce size of image files – don’t scale images in WYSIWYG editor It wont’t help. Compressing images using a good tool (even online) has a huge impact on page load speed. So compress and choose a right file format before you upload those images to your web server. Reduce number of images used to add visual effects. CSS 3 introduces a number of new features that significantly reduce the amount of work required to get desirable UI stylings: rounded corners, box-shadow, text-shadow or CSS gradients.
Because CSS sprites can reduce your page load time simply by reducing the amount of HTTP requests your page makes to the server through the consolidation of your CSS background images. Use them. Review the graphic elements on your template and used in modules, you’ll find the possibility of reducing the amount of files. Some time ago, I had optimize image files of the module, savings have reached up to 100 kb, only for background elements.
Remember to remove duplicate elements like graphic and scripts. It reduces performance to include the same file twice in one page. When it does happen, duplicate scripts creating unnecessary HTTP requests and wasted JavaScript execution. More files equals more load time. Unnecessary HTTP requests happen in Internet Explorer, but not in Firefox. This often happens if you site is using jQuery1.4.x for a component called “Component A” and another older component called “Component B” is using jQuery1.2.x then you site will load both of jQuery versions (!). You should and you want remove old jQuery script file. In such a situation would be helpful: Remove Scripts Plugin (from izerosoft.com).
Compress the code Whitespace is the spaces between your coding (in HTML and CSS files), removing the unneeded tabs and spaces can help a lot! Doing this will take a lot of extra bytes off the total size of your page and will speed up load time quite a bit.
Use tools that you have in Joomla! configuration panel, just turn on Gzip. I often see that the administrators forget about it. This is the most popular and effective compression method at this time. Gzipping generally significantly reduces the response size. Just check Site Performance section.
On JED (extensions.joomla.org) you will find lot’s of useful plugins which help you increase the speed of webpage loading. Some od them are really optimization “Swiss knives”, they can merge CSS and JavaScript files, compress HTML output, remove HTML comments, gZip JS and CSS files, and much more.
Extra boost methods
Last year, 2009, as part of Google’s initiative to make the web faster, Google introduced Page Speed, a tool that gives developers suggestions to speed up web pages. In November 2010, Google had introduced a module for the Apache HTTP Server called mod_pagespeed to perform many speed optimizations automatically.