There could be the number of possibilities why a website experiences slow loading. The possibilities are fed with the technical aspects in the server configuration and sometimes also with the way that the website has been developed. Most of the times The issues are resolved with simple changes in the server configuration. If the issue is fed with the website developed which is consuming more of the resources, then it needs to be optimised with the coding level.
Sometime there could be a network issue from the server, Which is very rare as we have network connections from at least 8 providers. If the website is slow, We sometime ask you to send the tracert or ping result. Please send it.
More than 98% of the time, This is the issue. Whatever it may be the server specification or speed, If the website is poorly designed and developed and not properly optimized, then nothing can be done from server side. It has be optimized by the web developer.
Some of the best tools to find out why your website is loading slow.
You can ensure that, There is no server side problem by following the simple test.
Did this page load in under 3 seconds?
When you have more number of request, then your website will load slow.
And also the the total page size should be less than 2 MB.