An external web-development company made a WordPress website for us. The website runs really, really slow on our server. They say that our server is slow. We say that their code is not optimized.

What tools to use to see why the webpage loads slow? Is our server slow or is the code not optimized?

  • Are the web tools good enough that can be freely found by Googling

  • Are there any other "free" tools? What to look for?

  • I have root access to the server. Any useful test to run from the web server?

  • Our server runs on CentOS, Apache 2.4, PHP 8.1, MySQL 5.7, WordPress 6.0

  • You could ask them to put it on their fast server to prove to you that the server is the issue. :-) Jun 21 at 14:32
  • There is no single answer, and in my experience the problem is likely a combination of factors. A good starting point is to use Google Lighthouse (built into Chrome - Burger Bar -> More Tools -> Developer Tools. One of the tabs on the top is Lighthouse). This will analyse the page, rate its speed and suggest improvements. Once you have these you can narrow down where the problems are. This won't say if the problem is your servers or the Wordpress code, but it will help you work out where the bottlenecks are, which can help you deduce it.
    – davidgo
    Jun 22 at 9:12
  • As you have root access to the server you can use vmstat, top, iotop and other resources to see how your server is performing. Likewise, if you take a copy of the site and see how it performs with plugins disabled you can see if the problem relates to specific plugins or combinations - which is a common Wordpress issue. Really though, if you need to ask this question you should not be offering commercial hosting as you have yet to attain the skills to do so proficiently.
    – davidgo
    Jun 22 at 9:16
  • Also, expecting optimized code from Wordpress is an unreasonable expectation. Wordpress tries - with admirable success - to be be all things to all people. Its "good enough" for many cases which is why its the largest website platform, but if you expect optimized code you will not get there in wordpress as Wordpress itself is not optimized for performance. That's why there are so many cache and optimization plugins for it.
    – davidgo
    Jun 22 at 9:22

1 Answer 1


I think a good start is to use our browser, Chrome, Brave, Firefox (and probably others) have an Inspect Command (as a right click menu).

Once the page has opened up, select the Network tab. And refresh your page.

It gives both a waterfall view and a tabular view with items and times to load. Start by looking at the slowest item.

If you are repeating the test, then ensure that you have flushed the cache. [Ctrl] [Shift] [Del] works on these browsers to a full flush. or a [Ctrl] [F5] will refresh it (it's called Hard Reload).

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