Full HTTP URL vs document root URL performances

Question

I noticed a performance degradation when in my webpages I use the full HTTP URL to load an image.

Let's say my website is on mydomain.com. Let's say images are all in mydomain.com/imgs directory.

It seems it's slower when I place images in the webpage using the full URL format:

<img src="http://mydomain.com/imgs/someimg.jpg"&gt;

rather than doing:

<img src="/imgs/someimg.jpg">

Same issue for loading JavaScript/CSS files.

Is the web server on mydomain.com taking more time to get images/fiels when using full http url (still on mydomain.com) compared to document root paths???

Answer 1

You problem is likely just that there is overhead in DNS lookups or something when accessing locally. Internet users will not notice the difference.

Answer 2

Oh this could be a slap on the forehead moment.

• When running locally and using the relative path the files are coming off your hard drive.
• When running locally and using an absolute path to a live server its having to go over the wire out on to the internet.

Answer 3

There is no difference. The browser always needs the absolute URL to retrieve the resource. So the relative URL needs to be resolved to an absolute URL. But that is absolutely negligible.