Understanding CDN for jQuery

A Content Delivery Network (CDN) hosts content for users through large distributed systems. The advantage of using a CDN is to improve the performance. When using a CDN to retrieve the jQuery library, if the files have been downloaded earlier, they will not be re-downloaded. This can help you improve the response time.

How to do it…

The following CDNs are available for jQuery files:

• jQuery's CDN provided by MaxCDN
• The Google CDN
• The Microsoft CDN
• The CDNJS CDN
• The jsDelivr CDN

To include jQuery on a web page, the URL of the respective CDN can be used so that files can be directly served from the CDN instead of using the local copies. The following table summarizes the respective CDN URLs for jQuery files:

CDN	URL
jQuery's CDN	Version 2.x: http://code.jquery.com/jquery-2.x.x.js http://code.jquery.com/jquery-2.x.x.min.js Version 1.x: http://code.jquery.com/jquery-1.x.x.js http://code.jquery.com/jquery-1.x.x.min.js
The Google CDN	Version 2.x: https://ajax.googleapis.com/ajax/libs/jquery/2.x.x/jquery.js https://ajax.googleapis.com/ajax/libs/jquery/2.x.x/jquery.min.js Version 1.x: https://ajax.googleapis.com/ajax/libs/jquery/1.x.x/jquery.js https://ajax.googleapis.com/ajax/libs/jquery/1.x.x/jquery.min.js
The Microsoft CDN	Version 2.x: http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.x.x.js http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.x.x.min.js http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.x.x.min.map Version 1.x: http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.x.x.js http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.x.x.min.js http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.x.x.min.map
The CDNJS CDN	Version 2.x: https://cdnjs.cloudflare.com/ajax/libs/jquery/2.x.x/jquery.js https://cdnjs.cloudflare.com/ajax/libs/jquery/2.x.x/jquery.min.js https://cdnjs.cloudflare.com/ajax/libs/jquery/2.x.x/jquery.min.map Version 1.x: https://cdnjs.cloudflare.com/ajax/libs/jquery/1.x.x/jquery.js https://cdnjs.cloudflare.com/ajax/libs/jquery/1.x.x/jquery.min.js https://cdnjs.cloudflare.com/ajax/libs/jquery/1.x.x/jquery.min.map
The jsDelivr CDN	Version 2.x: https://cdn.jsdelivr.net/jquery/2.x.x/jquery.js https://cdn.jsdelivr.net/jquery/2.x.x/jquery.min.js https://cdn.jsdelivr.net/jquery/2.x.x/jquery.min.map Version 1.x: https://cdn.jsdelivr.net/jquery/1.x.x/jquery.js https://cdn.jsdelivr.net/jquery/1.x.x/jquery.min.js https://cdn.jsdelivr.net/jquery/1.x.x/jquery.min.map

Using CDNs for new releases

Note that CDNs may not have the latest files when new versions of the jQuery library are launched since it usually takes a couple of days for third-parties to update their files. In the case of new releases, always check the available version before downloading them.

How it works…

CDNs consist of servers situated in data centers in strategic locations across the globe. When a client requests a resource from a CDN, the server that is geographically closest to the client processes the request. These servers are also known as edge servers. In addition to this, edge servers have a caching mechanism to serve various assets. All this helps you improve the client's response time.

See also

The Using NuGet Package Manager to download jQuery recipe