Why Use a CDN? Here are 10 Data-Driven Reasons

Let’s ask the most obvious question — why use a CDN? When you can still deliver your content, run your website, upload images, and videos, then would you want to spend some extra dollars buying a CDN service? This raises one more question- If hosting providers are doing the magic then what special CDN service providers do?

One simple answer could be user experience enhancement. By speeding the content delivery, a CDN can enrich the user experience and induce the other benefits that come with it. However, is it the only benefit of CDN? Is speedier content delivery the only benefit that encourages so many businesses to implement a CDN solution?

Here, we aim diving in-depth to a deeper comprehension of how a CDN integration lays a foundation for an array of many other welfares. Benefits that help your business stay ahead of the competition and prompt a multi-facet utility.

What is CDN?

What does CDN stand for? It expands as a Content Delivery Network. A physical network of interconnected nodes of the internet. The nodes refer to various systems and servers. This network speeds up the content delivery by caching the content on different nodes (systems and servers) and delivering it to the nearest end-user who is requesting the same.

CDN is being used by different websites and apps these days to push the content delivery speed and make browsing pleasant across the internet. Websites and apps use CDN content delivery for an array of a content type such as-

· Text

· Graphics

· Scripts

· Media files

· Open-source Software

· SaaS software

· Documents

· Portals

· Live video streaming data

· on-demand video streaming media and

· Social media networks

For all types of content, a CDN platform replicates them on hundreds of servers in their network so that the content is delivered as quickly to as many users even during peak loads.

Just take Netflix or Amazon Prime for example. When Netflix uploads the most awaited movie or Amazon opens an amazing flash sale, millions of users across the globe visit the site at once. A normal website host server could not process this immense traffic at once. This is where CDN jumps into action and do the magic.

How CDN works?

To understand the concept of CDN content delivery, let’s first understand how things work without CDN. The Internet is massive.

A user making a request to a website could be a thousand miles away from the hosted server (origin server). Traveling a great distance through the web of unlimited wired and wireless networks, and after going through the Fiber Optics Latency, the request is delivered finally to the user. Now, the time taken by the origin server to deliver the requested content is highly influenced by the distance it had to travel forth and back.

This is how it happens without a CDN-

1. A user sends a request to a web server

2. The web browser transmits the request to the web server.

3. The web server responds in single or multiple packets.

4. Each packet could take the same or different path to travel across the Internet and reach the web browser.

In all this, the packets travel through various sub-networks, which interconnect with each other. It goes through a path that involves Client >ISP>Internet>Origin Server. Hoping from nodes to nodes, networks to networks, the packets reach the client.

Now, if the distance between the origin server and the client is minimum, the connection will be faster. Things go wrong when distance both the nodes are far away from each other. The packets reach the client at a slower speed. Here, you wish if the origin server was nearby, or there would have been an alternate source to get the requested packets.

This is what CDN does. It acts as that alternate source, which stores the data as cache and serves it to the nearest client requesting the same. So whenever there is a request, the CDN will have the content in the nearest node to process the request in the least time.

A typical CDN involves 4 parts or nodes:

1. Delivery nodes — Stores the cache and delivers the data requested by the nearest client.

2. Storage nodes- provides the data, which is then cached and stored in delivery nodes.

3. Origin nodes — The actual web server where original data is stored.

4. Control Node — Systems and equipment that manage the back-and-forth movement of data. They manage tasks like hosting, routing, and monitoring.

Why CDN is a must for websites & apps?

The biggest websites and apps these days use CDN. Even the big blogging sites use CDN for faster page load. A few years ago, the case was a little different. One- there were comparatively fewer websites and apps. Two- the only important content to be transferred across the web were text, HTML, scripts, and images.

By 2019, the scene is way different. Today, an average web page comprises complex scripts, massive server-side requests, and heavy content. It has become difficult for regular servers to process the web pages and serve the requests faster. According to httparchive.org, an average web page weighed 2,409 KB in 2016, which is huge considering the same was 702 kB in 2010. This is a massive increase of 243%.

By making the process speedier CDN delivery keeps the pages faster and reduce the load on the origin server. As a result, even the massive video content transfer can take place with no hassle using CDN video streaming and video CDN. Without CDN, American Netflix would have crawled instead of thriving in over 190 countries of the globe. Even Facebook would have been restricted in the US or maximum to the neighboring states. CDN has helped websites and their business go global.

I can give another example. Twitch, one of the most popular live streaming platform in the US is hardly popular in a big South Asian market -India. It is because Twitch doesn’t have servers (CDN) in India. It makes it very difficult for Indian Twitch streamers and even viewers to stream in the normal internet bandwidth. Though people stream, the experience is not as good as it is in the US, where they have a CDN.

Besides the performance, user experience, and speedier content delivery, CDN offers many other benefits to the websites, apps, and business.

1. Reduces the page loading time

We cannot go beyond without mentioning the most fundamental reason for CDN integration. A CDN collects the data from the nearest node. As a result, the total distance a request needs traveling reduced exponentially via a content delivery network. Ultimately, it also abridges the time required to load the page post receiving the data. Reducing the cost of TCP and TLS handshake.

2. Reduces latency in video streaming

The same benefit explained in the above point also helps to reduce the total time required for placing a request and getting the response from the server. It equally applies to dynamic content like video files. By reducing the time-frame, a video CDN-designed, especially for dynamic content, reduces the video latency. Ultimately, the end-user faces fewer jitters and better video streaming quality.

If we look at the video CDN comparison, we can find two types of video CDNs being utilized for streaming these days:

A. On-Demand Video CDN: Completing based on caching, which prevent the requirement for direct download to stream a video. The buffering works in two ways. One –multiple CDN servers pull and store the content as a cache from the origin OTT server. Two –nearest CDN servers continuously buffer the content in small chunks to the streaming device. Ultimately, reducing the time and bandwidth required to play a video once clicked on.

B. Live stream Video CDN: Video CDN works on caching, but we cannot cache a live stream starting directly from the origin server. The question of the hour is –how live video CDN works in this case? A live streaming CDN works by either displaying ultra-high bandwidth pipes to transmit content instantly to users or uses multiple low bandwidth pipes, which depends on reflectors that speed up the content transmission. Of course, live streaming CDNs are costlier than on-demand video CDN.

3. Lowers the bandwidth consumption

Traditional web hosting is not enough to bear heavy loads of modern day websites and mobile apps. Instead of directly pulling the data from the origin server, it is always better to get the same through edge servers installed in a CDN. It does not only reduces the computations required but also delivers high-quality media in a shorter span. Ultimately, holding the resources for a shorter duration and reducing the bandwidth requirements. This saving on the bandwidth will reduce the load from the origin server and consequently result in cheaper bills from your hosting partner.

4. Helps to boost SEO

Page loading speed is one of the signals that Google uses to rank the pages in its SERPs. The faster your website is, the better are the chances for pushing to the top ranks in the SERPs. Another important factor is image utilization. Google indexes images more frequently than any other content on the web pages. However, with normal web hosting, you cannot utilize many images on your webpage as it will make the page load slow.

Luckily, CDN makes things quite easy. You can host your images on the CDN and get them loaded on the page with lightning fast speed. Most of the big blogging sites use CDN. There are also dedicated and cheaper CDN services for image hosting. In fact, you can also improve your blog quality by using Gifs, which are generally too heavy for traditional servers. You can always compare your web pages with CDN and non-CDN images using Google’s website speed testing tool to confirm my statement.

5. Lowers the investment in the long run

There is a myth that CDN integration is very costly and it is meant for those giants only. No doubt, giants cannot survive without CDN, but CDN in 2019 is affordable. CDN service providers offer various cheaper plans for small to medium-sized websites. As discussed in one of the previous points, there are also image-specific CDNs, which are cheaper. Bottom line is –they do not limit CDN to big sites. You can always find a good CDN service fitting your budget and requirements.

Moreover, CDN is way cheaper in the long run. They bear almost 60+% of your total website load. This load sharing with the origin server result in lower bandwidth consumption. Ultimately, reducing the bill you get from the web server hosting partner.

6. Gives a better analytics

By distributing the resources to multiple nodes, CDN optimizes the load capacity per user request. With real-time statistics and analytics, you can get a better insight into how traffic is coming to your site. Each node will have more solid data about the traffic it generates. In this way, you can always figure out the regions where you need to focus your efforts on.

7. Gives expandability and scalability

Depending on your CDN hosting partner, you can always expand your reach to the regions where it serves. A large number of nodes means better scalability. Be it any resource of any size, you can always be ensured of a high-quality delivery with greater reliability.

8. Gives stability during peak time

Where traditional servers cripple during the peak load, CDN servers distributed evenly across the network share the load and keeps the website live. In fact, even if one node fails, you can always expect the other nearest nodes to take on the load and serve the requests. Ultimately, keeping your website up, running and stable even during the heavy loads.

9. Protects against DDoS attacks

DDoS occurs when attackers hold the recourses on your server by pushing a heavy load to it. It crashes a traditional server and takes your website down.

CDN edge servers play the role of a blanket for your traditional origin server from DDoS attacks. One –they bear most of the load on your website and keeps it up and running even if one node fails. Two –attacks on your origin server will have to go through the edge servers which do not fail you because of the decentralization of the data.

Moreover, you can integrate SSL, which helps in mitigating DDoS by self-expiring the access to a resource for a limited time. That means attackers cannot hold your server’s resources for a long time even if they somehow can access them.

10. Boosts business via UX enhancement

All the benefits mentioned above eventually add-up to the overall user experience of your website. From website speed, stability, and SEO benefits to protection from DDoS, everything ultimately leads to better conversion rates.

Did you know that 74% of your visitors will leave your site if it does not load in 5 seconds? In fact, 54% of the visitors will ditch you post 3 seconds itself. Source

The following stats from Google page load time study will give a clear comprehension of how a delay of even a single second can degrade your overall business:

· With 1–3 s load time, you have 32% bounce back probability.

· With 1–5 s load time, you have a 90% bounce back probability.

· With 1–6 s load time, you have a 106% bounce back probability.

· Wit 1–10 s load time, you have a 123% bounce back probability.

These are the stats for 2017. Just think about the case in 2019. Undoubtedly, it must be significantly higher. So with every second you improve, you get solid visitors, reduced bounce rate, improved UX, and a greater chance for conversion.


Are you still confused about why use CDN? As you can see the overall benefit of a CDN integration, I don’t think there could a doubt. Whether you own a blog, an eCommerce site, a social media site, or a video streaming site, you can find a suitable CDN for each. With some research, you can easily find even the cheaper CDN providers for your cause. Maybe, a trial of the same might help you compare your site pre and post CDN integration. There are many CDN services, which offer free trials. Just Google it and you will find. However, I would suggest you perform deeper research before finalizing a good CDN service for your kind of cause.

Why Use a CDN? Here are 10 Data-Driven Reasons was originally published in Hacker Noon on Medium, where people are continuing the conversation by highlighting and responding to this story.