Images, CSS and Javascript on subdomain or external website

[Happy-SEO]

Hi guy's,

I came across webshops that put images, CSS and Javascript on different websites or subdomains. Does this boost SEO results? On our Wordpress webshop all the sourcescodes are placed after our own domainname:

www.ourdomainname.com/wp-includes/js/jquery/jquery.js?ver=1.11.3'
www.ourdomainname.com/wp-content/uploads/2015/09/example.jpg

Examples of other website:

Website 1:
https://www.zalando.nl/heren-home/

Sourcecode:
https://secure-i3.ztat.net//camp/03/d5/1a0168ac81f2ffb010803d108221.jpg
https://secure-media.ztat.net/media/cms/adproduct/ad-product.min.css?_=1447764579000

Website 2:
https://www.bol.com/nl/index.html

Sourcecode:
https://s.s-bol.com/nl/static/css/main/webselfservice.1358897755.css
//s.s-bol.com/nl/upload/images/logos/bol-logo-500500.jpg

Website 3: 
http://www.wehkamp.nl/

Sourcecode:
https://static.wehkamp.nl/assets/styles/themes/wehkamp.color.min.css?v=f47bf1
http://assets.wehkamp.com/i/wehkamp/350-450-layer-SDD-wk51-v3.jpg

[JordanLowry]

The only major improvement I can think of hosting images externally would be improving the overall speed of your website. If you run a pagespeed test with Google's free tool and notice your site is rendering slow then I would first consider reducing the number of javascript and css files being loaded. You will run into issues if your site is loading too many external files you can expect to see increases in bounce rates and poor engagement metrics. This may have changed but Moz did an expierement awhile back on if website speed impacts search ranking however if certain pages are taking too long to load they probably

This may have changed but Moz did an experiment awhile back on if website speed impacts search ranking. Even if speed does not directly impact rankings if certain pages are taking too long to load they probably won't be indexed.

What I would do is run Google's page speed tool on a few pages and if you have Google analytics on your site you can get some insights by looking at Behavior-> Site Speed-> Speed Suggestions and check out some of the recommendations Google is making about your site.If you have a problem with

If you find out that you have a problem with speed I came across a good article on some tips and suggestions that may be helpful for you about reducing http request.

I hope this helps some.