Why we use wordpress plugins? Simple Answer is that we use wordpress plugins to add features to your site. Then our next question is that “Does a wordpress plugin affects your site load time?” Then we can say “Yes, A wordpress Plugin can affect your site load time.” How a wordpress Plugin affects the load time of a site.
We use different plugins to add features in wordpress site e.g. Contact Form, Image Gallery, EmailChamp, popup box and etc. Plugin is like an app to perform a functionality. When we add a plugin in our site it means that we include all the file in our site that wordpress plugin have. When a user visit our site browser load all wordpress file and all the file that a wordpress plugin have . It implement all the database quries, each line of code ,all stylesheets ,all javascript files, images and etc . This make multiple requests on your site and each request increase your load time.
How to check load time?
To check the affect of plugis on your load time .Deactivate all the plugins and open your site and Righ click on site page menu appears Select Inspect in Google Chrome and Inspect Element in Firefox. Then Developer tool panel will appear. Click on Network tab
Now Reload your page File that are Loaded will show with their load time. After the page stop loading you can count your load time. Activate your plugins and reload the page. After activation of plugins when you reload the page the number of files in networks tab will increase and each file take its load time then. Then load time will increase.
How we can control a WordPress Plugin?
To overcome the affect on your site you can use wordpress plugins that are well coded ,have good review and recommended By a trusted source. If a plugin is affecting your site then you have to find a new plugin which do same job but better. If you cannot find another plugin and you cannot live without it .Then you have to find the extra points like Stylesheet files, Javascript files or some sort of code. You can restrict its code on specific page.