The scores
PageSpeed and YSlow presented in the GTmetrix report represent the web development quality of your page.
The
Page Size is the size of all resources that are required to load your website and is related to web development.
The
Requests is the total amount of web requests that are required to load your website and is also related to web development.
External resources can also slow your page, such as advertisements. In the case of advertisements, you can enable the
Adblock Plus option and check the score of your site without advertisements.
The
Onload Time represents the time it is taking to load all the resources on your website, and also depends on the distance between the GTmetrix server and the location of your server. For this reason, you should always select the closest GTmetrix server in relation to the location of where your website is hosted. E.g.: if your server is hosted in the US, you should also select the US location for the Server Region in GTmetrix.
Some sites, because they have a lot of resources to load, can get a more positive result in
Onload Time in GTmetrix after enabling the option
Stop test onload. The option allows GTmetrix to consider that the page has finished processing after all the resources (images, CSS, etc.) of the page have finished downloading. More details on the official page at
https://gtmetrix.com/faq.html#faq-fully-loaded-vs-onload.
If the scores on
PageSpeed and YSlow are bad, the
Onload Time is generally bad as well, depending on the total size of the resources and requests to load your page.
