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Navigating the Cloud: AWS Savings Plans vs. Reserved Instances

In the ever-evolving world of cloud computing, Amazon Web Services (AWS) continues to provide businesses with flexible options for optimizing their cloud spend. Two key solutions that many AWS customers rely on to reduce costs are AWS Savings Plans and Reserved Instances (RIs). In this blog post, we'll dive into the differences between AWS Savings Plans and Reserved Instances, helping you make an informed decision about which one is right for your organization.

What Are AWS Savings Plans and Reserved Instances?

Before we delve into the distinctions between the two, let's quickly recap what each of these cost-saving mechanisms entails:

  1. Reserved Instances (RIs): Reserved Instances allow you to commit to a specific instance type, region, and term (one or three years) in exchange for a lower hourly rate compared to On-Demand instances. RIs have long been a go-to choice for enterprises with predictable workloads, offering substantial cost savings when workloads are static and well-defined.
  2. AWS Savings Plans: Savings Plans are a more flexible cost-saving option introduced by AWS in late 2019. They offer savings on your compute usage in exchange for a commitment to a certain dollar amount per hour, rather than committing to specific instances. This flexibility allows you to adapt to changing workloads and instance types more easily.

Key Differences

Now, let's explore the fundamental distinctions between AWS Savings Plans and Reserved Instances:

  1. Flexibility vs. Specificity: AWS Savings Plans are known for their flexibility. They allow you to apply your savings across a wide range of instance families and sizes, regardless of region. This adaptability is invaluable for businesses with dynamic or uncertain workloads. On the other hand, Reserved Instances are more rigid, requiring you to choose specific instance types and regions when you purchase them.
  2. Instance Type Agnostic vs. Instance Type Specific: With Savings Plans, you can switch instance types without losing your cost savings. As long as you're spending the agreed-upon amount, the flexibility extends across instance families. RIs, on the other hand, lock you into a particular instance type, limiting adaptability.
  3. Elasticity: AWS Savings Plans automatically adjust to your usage, making them ideal for applications with variable workloads. They apply your savings to any applicable usage in your account, providing cost benefits even when you scale up or down. RIs, in contrast, require you to predict your future usage and instance types upfront.
  4. Applicability: While both RIs and Savings Plans offer savings on compute costs, Savings Plans can also be used for services like Lambda and Fargate, making them versatile for various AWS workloads. Reserved Instances, primarily designed for EC2 instances, have limited applicability outside of this use case.
  5. Term Lengths: RIs come in either one-year or three-year terms, offering more extended commitments for greater savings. Savings Plans come in one- or three-year terms as well but offer more flexibility within those terms.

Which One Should You Choose?

Selecting between AWS Savings Plans and Reserved Instances depends on your organization's unique cloud usage and business goals. Here are some general guidelines:

  • Choose AWS Savings Plans if your workloads are unpredictable, dynamic, or involve various instance types, and you need a more flexible cost-saving solution.
  • Opt for Reserved Instances if you have well-defined, predictable workloads and can accurately forecast your instance needs for one or three years.

In many cases, a mix of both might be the best strategy. This hybrid approach combines the flexibility of Savings Plans with the predictability of Reserved Instances, providing a balanced solution for your organization's cloud cost optimization.


In the complex world of cloud cost management, AWS Savings Plans and Reserved Instances offer valuable tools to help your organization reduce expenses. By understanding the key differences between the two, you can make an informed decision and create a cost-effective strategy that aligns with your business needs. Remember that cloud cost optimization is an ongoing process, and regularly reviewing your usage patterns and cost-saving mechanisms will help you make the most of your AWS investment.

Reyki AI specializes in optimizing cloud compute costs on your behalf, whether that's using Savings Plans or Reserved Instances. Onboard onto to automate more than 60% of your cost reduction on AWS today.

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