
WordPress: Premium theme vs Custom Developed Theme
When it comes to website performance, every millisecond counts.
WordPress CMS has several premium themes with templates of almost every category / genre. This is a great option for someone who is looking to jump start their website development. However, this is arguably the biggest weakness of the premium themes as well, that they are written to work with every kind of website.
Premium themes usually come with “settings” or “options”, that users can modify as per their requirements. Now, in terms of WordPress, each setting or option is a database query. Whether you have activated an option or deactivated an option, every time a page is loaded, WordPress has to make a database query to know the user’s choice for that option. Fortunately, WordPress is designed to cache most of these type of database queries but not all of them.
We took the following screenshot of homepage from one of our websites, designed using a premium theme. The website is highly optimized and none of the plugins are loaded on the homepage and yet the website makes ten database queries on each page load. All these queries are from or due to the premium theme on the website.

Premium themes also come with a lot (sometimes hundreds) of modules or widgets to design a website. This is good for someone who has little to no knowledge of coding and could just drag and drop the module or widget to design a website. But this comes at a huge cost of memory usage and page generation time. Whether someone uses two widgets or ten widgets on a particular page, WordPress has to load and process the whole theme to generate the page. It means no matter whether user has used all the widgets or not, WordPress has to load all the widgets into the memory.
As you can see in the above screenshot, the premium theme has used 60.8 MB of RAM, which is about 12% of the server resources to generate a single homepage in 814.3 milliseconds.
On the other hand, MathYug has a theme that is custom developed especially for the MathYug website. The following screenshot of the website’s homepage shows that the RAM usage is just 8.8 MB, which is less than 2% of the server resources. MathYug’s homepage has additional features and animations, yet the page is generated in just 68.2 milliseconds.

The premium theme is using about 7 times more server RAM than our custom developed theme and the page generation on the premium theme is about 12 times slower than the page generation time on our custom developed theme.
Premium themes are not bad. On the contrary, they are great but for someone who is new to the website development or wants to launch a website as soon as possible.
And for the serious business websites, especially with eCommerce and LMS functionality, where each millisecond counts; no premium theme can beat the performance of a custom developed theme.