When it comes to the web, speed is everything. Study shows that if your site takes more than 4 seconds to load, the visitor will navigate to another site.
A good way of measuring how fast your site is and to improve its speed is to run a scan at http://gtmetrix.com
I ran a scan on wpaid.net and the results are below:
Gtmetrix provides suggestions on how to optimize the site under “Breakdown” after you ran the scan.
The site received F on Minify CSS, Levearage Browser Caching and Enable Gzip Compression
Those can be resolved by installing a caching plugin such as W3 Total Cache or WP Super Cache.
I installed W3 Total Cache and that increased the Page Speed and Yslow Grades to B with a load time of 1.10 seconds.
For W3 Total Cache, I recommed turning Database and Object Cache off since those tend to cause issues.
Even though caching improved the speed and grades for the site, caching is not the end of the story. You can optimize your images by using a plugin such as WP Smush it
Optimizing images in my case did not make that much of a difference since I already had images that were optimized.
Expire headers can be specified by adding the code below to your .htaccess file
After adding that to the .htaccess file, the Page Speed grade increased to A with the Yslow grade still at B
There were still optimization steps such as avoiding @import for CSS. The current theme had @import in one of the CSS files and to avoid this, I combined both CSS files into one. That changed the Page Speed Grade to 92%.
Loading scripts from external scripts and images may also hurt the performace of your site. Majority of the issues with the site at this point has to do with scripts loading from pagead2.googlesyndication.com
From the image above, the site still scores a C on Specify a Vary: Accept-Encoding header because of the scripts loading from googlesyndication.com. Unless it is absolutely necessarily, avoid loading scripts from external sites since you have no control over how to cache those resources.
In this case, the scripts from that URL is for Google Adsense which is needed on my site so I chose to leave it.
Another optimization step is to disable Etags. By removing the ETag header, you disable caches and browsers from being able to validate files, so they are forced to rely on your Cache-Control and Expires header.
To disable Etags, add the code below to your .htaccess
Header unset ETag FileETag None
With all the optimizations above the results show
At this point it appears my only issue is the script for Google Adsense. I temporary disabled it and the results show A for both Page Speed and Yslow.
What if you site is still slow after following all the optimization steps from Gtmetrix ? The issue may server related but even before blaming the server, I suggest turning off all your plugins then run a test from Gtmetrix. You can analyze your plugins with a profiler such as P3 http://wordpress.org/plugins/p3-profiler to find the one using the most resources.
You can also switch to a theme such as twentytwelve for WordPress. Certain themes look great but can slow your site down due to how they are coded.
If using another theme and disabling all your plugins does not make a difference its time to contact your host to check the server to see if there are any issues.
If you need help optimizing your site both client and server-side, you are welcome to contact me.