A multi-CDN (content delivery network) infrastructure refers to using more than one CDN in your content delivery strategy and tooling. Multi-CDN has become a standard practice among large content providers and media networks, particularly streamers - this architectural strategy yields better resilience from downtime and outages, enables global scalability, and helps customers enjoy the best possible user experience.
By having more than one CDN in play, a business has both a ‘back up’ option in the case one CDN goes down, and the option to intelligently and strategically route internet traffic between the two CDNs, depending on internet ‘traffic’ - or times when one CDN may see large traffic spikes that impact internet performance.
What are the benefits of a multi-CDN infrastructure?
Redundancy: A multi-CDN strategy delivers the key benefit of redundancy (you can think of this as a diversification of risk) - with multiple content delivery networks in play, an organization can strategically route delivery paths to sidestep outages, bypass local bottlenecks, and deliver content quickly and with the highest fidelity, reducing the associated risks and costs of downtime.
Uptime: When an organization runs their multi-CDN infrastructure efficiently and effectively, they can guarantee uptime, and can deliver content via the fastest possible route to their customer. Even in an environment where one CDN is strongly preferred for performance reasons, for example, other CDNs can provide peak offload and basic backup on demand. A collective win for both the organization and the customer.
Dynamic routing: This capability allows companies to choose the most performant network, based on the capacity and localized performance. Multi-CDN services focused on easing integration between different content delivery networks allow publishers to gain better insight into the end user’s quality of experience. While having great content will always be the top priority for publishers, the importance of reliable, low-latency, minimal rebuffering, and high-bitrate delivery, adopting Multi-CDN features should be the No. 2 priority for any publisher. Both live and video on demand need multi-CDN capabilities to deliver the best quality of experience to users.
What are the challenges of implementing a multi-CDN infrastructure?
While a multi-CDN infrastructure isn’t a new concept, organizations still struggle to effectively and accurately measure and optimize their CDN performance, thereby limiting their ability to strategically allocate traffic across different CDNs, or make improvements to their processes.
Effective use of a multi-CDN approach requires detailed and real-time information about each of the CDNs within the architecture, and the capability to make decisions and work with those CDNs based on access to real-time actionable data. Running an effective multi-CDN architecture is hard!
As a strategic partner in the multi-CDN space, Fastly sees firsthand the lack of strategy, accuracy and insights most organizations still grapple with across their complex multi-CDN environments. Orgs often fly blind, making decisions based on poor or inaccurate data, and therefore miss out on enormous cost and performance optimization opportunities. Fastly helps our customers bridge the data and knowledge gap of poor traffic insights, serving as a strategic partner to any multi-CDN infrastructure.
Key challenges include:
Lack of visibility into quality of experience (QoE) issues
Inefficient routing across the multi-CDN deployment
Lack of visibility into vendor platforms
Poor insights resulting in: lowered traffic allocations or misinformed decisions based on misconfigurations or bad data
What good multi-CDN implementation looks like
Any multi-CDN optimization effort needs to have the following outcomes and capabilities:
Cost reduction. With a variety of bandwidths, latencies, and prioritizations available through content delivery networks, content publishers need the ability to shift between low cost, low-priority traffic, and high-cost premium bandwidths.
Real-time switching. Based on analytics, content should be able to be switched between content delivery networks, even mid-stream, without any degradation in quality of experience.
Traffic customization for devices. Traffic destined for laptops should have the ability to be configured differently than traffic for phones or smart TVs.
Easy, comprehensive analysis. Content providers should be able to do A/B testing and the troubleshooting necessary to isolate incidences
Configure traffic by content type. Any Multi-CDN solution should allow rules that deliver video traffic and web traffic separately, so the two media types can be prioritized by cost and performance requirements.
What are the best multi-CDN solutions?
Capability / Feature | Fastly | Cloudflare | Akamai | AWS CloudFront | Google Cloud CDN |
Core positioning | Programmable edge platform (real-time control) | Integrated platform (CDN + security) | Enterprise legacy CDN + services | AWS-native CDN | GCP-native CDN |
Performance (latency / TTFB) | Top-tier globally; excels in dynamic content | Very strong globally | Strong, especially with deep peering | Strong via AWS backbone | Strong in GCP regions |
Edge compute capability | Compute (Wasm, ultra-low latency) | Workers (large ecosystem) | EdgeWorkers | Lambda | Cloud Functions |
Config changes / agility | Instant, real-time configuration updates- no deployment lag | Fast but more abstracted | Slower, enterprise workflows | Slower (propagation delays) | Moderate |
Cache purge speed | Industry-leading: instant, globally | Instant | Fast | Slower | Moderate |
Customization / control | Very high | Moderate abstraction | Very high but complex | Moderate | Moderate |
Dynamic / API workloads | Best-in-class (designed for real-time apps) | Good | Good | Moderate | Moderate |
Developer experience | Strong (API-first, IaC friendly) | Very easy but less low-level control | Complex, enterprise-heavy | Familiar for AWS users | Familiar for GCP users |
Security (WAF, DDoS) | Strong modern security stack | Very strong built-in | Strong | Add-on | Add-on |
Network design philosophy | Highly optimized POPs (efficiency over density) | Large distributed network | Large global footprint | Large | Large |
Pricing model | Usage-based, transparent at scale | Flat and tiered | Custom enterprise contracts | Usage-based | Usage-based |
Best use case | Real-time apps, APIs, personalization, streaming | SMB: enterprise all-in-one | Global enterprise, media | AWS-centric apps | GCP-centric apps |
How Fastly can help
A multi-CDN strategy helps organizations build a faster, more resilient content delivery layer by combining redundancy, performance optimization, and cost efficiency. By distributing traffic across multiple CDNs, companies can more seamlessly reroute around outages or regional bottlenecks, maintaining uptime while reducing the risk and cost of downtime. Intelligent traffic allocation ensures users are always served through the fastest available path, delivering consistently high-performance experiences worldwide.
Fastly’s CDN is uniquely equipped to serve as your strategic partner in optimizing your multi-CDN architecture for performance. All of our largest customers are multi-CDN; over the years, we’ve found they often lack a strategy for how to measure their CDNs’ performance, and how to allocate traffic across different CDNs.
We have successfully partnered with many of them, yielding enormous performance benefits. We sit with our customers and help analyze and evaluate their set up and identify any ‘gotchas’. We’ve seen it all - making it easy for us to help you measure the quality of your users’ experience, and provide the visibility you need in order to make informed content routing decisions. Fastly can help provide you with the visibility into local networks, using the context of performance metrics your organization cares about and measures itself against, and help you to make strategic improvements to your architecture - giving you visibility you need.