CDN is content delivery network that is a large system of distributed servers across different locations across the world.
The main purpose of a CDN is to present a large data faster from a nearby data server with less latency.
CDN is also used to reduce the bandwidth of large files on your hosting server. Since CDN can store large files the bandwidth and load on your hosting servers get reduced by a lot.
So for example you are running a website which is heavy on pictures or is heavy on videos CDN comes handy for you to not disturb the hosting server space as well as bandwidth and use CDN instead to host these media files whereas continue to host the site with your hosting.
Hence the need and use of CDN.
So thus CDN not just reduces space issues on your hosting but makes your site much quicker and faster to load.
List of Providers of CDN for WordPress
Here is a list of providers of CDN. We cannot say which one is the best because its for an user to decide which works out the best for them. But based on features we have listed them out:
1. MaxCDN
MaxCDN claims they have jquery, tnw, yoast and buysellads as their clients. MaxCDN has a dedicated plugin for WordPress which makes it easier for it to be integrated. Prices start as low as 4.25Cents per GB for under 15TB bandwidth. However tests show it is less faster than BitGravity and CacheFly. Starts at $9 per month.
2. BootStrap CDN
Bootstrap CDN unlike other CDN providers is used for storing all css,and javascript and jquery files. However Bootstrap and MaxCDN both are owned and controlled by NetDNA. Bootstrap CDN is although free of cost.
3. Cloudflare Free CDN
Cloudflare is another good CDN option for WordPress and it is quite seo friendly as well because it doesn’t renamed your pictures or videos url but actually asks you to point your hosting servers to the Cloudflare servers to load the site using cloudflare even when hosting is down. It is good for those who have a large content based website. Cloudflare has some security features as well like basic DDos Attack protection and harmful bot protection. They have their own firewall system to block harmful traffic. It is free for one site with some basic features and starts at $20 per month for 1 website.
4. Amazon S3 and Cloudfront
Amazon needs no introduction. S3 is a bucket like service where you can post your media and other large files and retrieve them easily and quite quickly without causing much of bandwidth as well as hosting space. Amazon Cloudfront is however a complete CDN solution for your website. It is optimized to work with all other amazon services like S3 and gives large data with low latency and at high speeds. Amazon S3 offers upto 5 gb free of cost storage.
5. Incapsula
Incapsula has prominently figured in many CDN review sites and has good positive reviews. They have their own firewall to tackle with harmful bots and hackers and speed up your website performance with their servers. It is a PCI compliant CDN service with backdoor protect and DDos attack protection.
6. Photon by Jetpack
Photon is by Jetpack i.e. an Automatic company product the same company which founded WordPress. So needless to say this is a good solution and ofcourse is free of cost. We tried to use Photon on our current site but had some problems plus it is not seo point of view wise to change to a CDN service for an already running site since all image locations get changed. Only cloudflare allows for hosting to be pointed so no change in image location. Photon is good for WordPress users with large number of images. Images get cached forever and hence your site loads faster.
7. KeyCDN
Targeted towards small businesses it has a pay as you go plan with no set up costs or other hidden charges at as low as $0.04 i.e. 4 cents per GB. Side by side performance testing placed KeyCDN at par with Akamai.
8. Akamai CDN
Akamai is a leading provider of CDN and has emerged as a global provider. One of the first ones to have CDN it has huge enterprises as clients like Cisco.com. Founded in 1998 it is one of the largest CDN providers in the world and is responsible for 15-20% of all web traffic in the world.
9. Internap
Provides CDN as well as hosting solutions. They have a patented MIRO technology which checks out of 11 major internet backbones the best one for you and delivers content and media faster. It was founded in year 2000 when CDN was probably very new and has been a major player since then.
10. Coral CDN
Coral CDN is for those who want to normalize or handle a traffic spike for a day. Just append .nyud.net to any url and you open that url in Coral CDN so basically Coral is loading it for you.
Hence a traffic spike created by marketing links or newsletter etc can be handled this way for certain times using Coral CDN. It is a free and open service and isn’t something for regular usage.
11. Press CDN
Press CDN is dedicated to making WordPress sites faster. It is relatively a very new company and utilizes a combination of Akamai, Amazon Web Services, Edge Cast and Max CDN. It’s pricing starts at as low as $9 per month for 50 gb CDN. So no more of hassles of setting up CDN accounts and take the advantage of some of the best using Press CDN.
12. WP CDN
WP CDN is yet another CDN created only for WordPress users. It offers an easy set up for WordPress users and also seo friendly cname url pointing so that one doesn’t have to modify much but host the images, javascript and css on cdn to fasten up the website. Pricing starts as low as $6 per month. And is targeted for bloggers and independent smaller business sites who want to use CDN.
13. Rackspace Cloud Files
Rackspace is a known name and is one of the best providers for Dedicated Servers around the world. They also have the Rackspace Cloud files service which is costly but is very efficient as a CDN. One can only take the Rackspace cloud files service if they wish to host their site somewhere else and only use Rackspace for CDN purposes. Enterprises normally take advantage of Rackspace due to their pricing structure.
14. Meta CDN
Meta CDN is a video streaming and audio and media hosting cdn which is a very good option for large sites who want to accelerate their websites. Their enterprise solutions starts as low as $39 per month with 500 GB monthly bandwidth for upto 3 websites.
15. Exabytes CDN
Exabytes is a Malaysian firm with hosting and CDN options for all clients. It is Malaysia’s no. 1 cloud servicing/hosting company. Pricing starts as low as $39 per month but they have 3 months billing cycle. Offers to support upto 5 sites. So if someone has more sites and needs a reliable CDN then it comes to $8 per site per month. However there are other options as well with similar pricing points.
16. Bit Gravity
Bit Gravity is another enterprise CDN service which is very good. Pros is it is very fast and can be used for HD video streaming. Cons are plans are not mentioned properly and after calling them they tell you to sign up for a 12 month contract. It scores higher than MaxCDN and Cache Fly and Akamai and Limelight in tests as is shown by review sites for CDN.
17. Cache Fly
Cache Fly appears as top No.1 CDN for 2013 on top 10 reviews website. It has all sorts of plans like pay as you go offers as well. It claims itself to be fastest but is one bit slow than BitGravity although our tests show similar results favouring CacheFly. They offer custom plans for each type of business and surely have been in business from 1999. So definitely reliable and recommended. Boosts of clients like LG, Adobe, Toyota and the likes.
18. CDN 77
Starts as low as $49 per TB. CDN77 is another enterprise solution for larger sites and offers TB and PB pay as you go and monthly and annual contracts. CDN77 offers users 50 GB storage space along with the CDN service for storing files.
However CDN77 has been launched in London from March 2012 so still it is yet to gain market as well as is a new company from CDN standpoint.
19. CDNify
CDNify is a 2013 launched service. Starts as low as $29 per month for a developer plan it is targeted for smaller businesses, bloggers and independent websites. One of the best features available for CDNify is that you can have multiple websites per account. Based on 10 TB it compares itself with Akamai, CDNnet and Edgecast and shows it is much less costlier than others. CDNify is new in the market but surely looks promising. Only time will tell how reliable it is.
20. ChinaCache
China Cache as the name suggests is a Chinese company based in China. Has been founded in 1998 and is one of the oldest ones to provide CDN services. Has notable brands like Mozilla, MySpace and 2008 Olympic Games amongst others. With its network it already is an established name in Asia and also has US presence. Pricing is lower than other enterprise solutions because of its Chinese presence. But offers solutions only via contracts just like other CDN enterprise solutions.
21. EdgeCast
Has been in industry for quite some time as has been launched in 2006. Has many patents to its name for CDN services. Have many kinds of solutions for consumers like open cdn, licensed cdn etc. However pricing isn’t transparent and one needs to sign up a 12 month contract with negotiations.
22. HighWinds
Highwinds was launched in 2002 and has been a reliable service since then. Comparable to enterprise solutions of Level 3, EdgeCast, and Akamai. However they surely have competitive pricing of $90 per month. But they have many kinds of pricing levels and different billing systems which make them lucrative for small businesses as well.
23. Level3 CDN
Level 3 communications manages its own network of Tier 1 Internet Backbone and hence has a reliable service. However it is costlier and only with negotiations one can get through contract of 12 months. Definitely recommended for large enterprises but for smaller businesses this isn’t a good solution. Because there are other cost effective solutions.
24. Limelight Networks
Limelight Networks is a major competitor for companies like Akamai, Edgecast, Level 3 and the likes. It is an enterprise CDN solution and has many services and solutions just like the other enterprises. It has been widely associated with many major brands over the years and amongst them notable are 2008 summer Olympics, Microsoft and Oprah’s webcast. Pricing wise it targets enterprises and hence pricing needs to be negotiated via contracts.
25. TinyCDN
Tiny CDN leverages amazon cloudfront and services but makes it easier for someone to integrate CDN into their website.
Other notable names in CDN are:
26. Net DNA
27. CDNetworks
28. ChinaNetCenter
29. Telefonica
30. Voxel
31. CDNsun
32. Windows Azure
33. HP Cloud Services
34. PageRain
35. Distil Networks
Get the complete list here: http://en.wikipedia.org/wiki/Content_delivery_network
So to sum it up there are FREE CDN providers, Commercial CDN Providers and Telco CDN providers as per Wikipedia.
Free CDN Providers are Cloudflare and Bootstrap CDN.