One of the increasingly discussed aspect of SEO is site speed. After optimizing the website internally its time to look for external tools to speed up the website. One of the options is to use a free CDN. A CDN is a Content Delivery Network which basically delivers the website to the visitors with least possible delay. In order to achieve the goal of improving the site speed, a CDN uses the servers located closest to the visitor to deliver the website content, thus improving the site speed and in turn the SEO.
Along with improving the site speed and SEO, A free CDN can also offer a host of other nice features such as security, load balancing, statistics etc. Our focus however remains improving site speed and performance.
The inner working of a CDN is quite simple. The servers within the content delivery network cache the site and deliver it’s content via the server located closest to a particular user. It is easy to visualize how bandwidth is saved and site performance is improved when user’s browser is downloading a photo from the closest server rather than the actual host located in a different country or state altogether. The photos and text are static content which can be easily cached by the edge servers but what about the dynamic content ?
In case of the websites that serve dynamic content, the CDN servers and hosting service provider needs to have much more frequent communication. The CDN has to keep checking for changes in the site to keep its cache most up to date. In case of dynamic websites, its therefore important to make sure that support for it exists in the free CDN that you plan to use.
For websites or blogs such as WordPress, Joomla which are used to host Google Adsense its important to check if its acceptable to use a CDN. One impact could be that Google Adsense might think that CDN servers are real visitors that are accessing the website rather than the actual visitors which are served by the CDN. This means that Adsense will serve ads relevant to the CDN server IP addresses causing the loss of revenue or in worst case scenario banning from Google Adsense if it thinks that website owner is trying to use illegitimate practices by accessing website from same ip addresses again and again.
List of Free CDN to improve site speed and SEO
1. Cloudflare : This is the first choice for a free CDN. It provides various plans for those who are willing to ay more for extra services. It doesnot have any limit on the bandwidth.Cloudflare requires least configuration to implement. Cloudflare however does not cache the dynamic content. More details here.
2. Incapsula : This is the next best option out there for a free CDN with extra rich security features. Any issues are complains are supported by the community. There are again no bandwidth limitations. Incapsula requires least amount of configuration to implement. Incapsula claims to have capability to cache dynamic content after learning about the site and how often it changes. More details can be found here.
3. Various : Another option would be to use any third party website which can let you host your content and then take care of its distribution on their own. For example video on youtube, pictures on flickr can give benefits of a free CDN. This however does require setting up accounts and using links of the third party website on your own to show the content. Also requires understanding of the ownership of intellectual property. Make sure that content you post on a third party website remains your intellectual property.