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Justin Justin is a freelance writer and full-stack developer that enjoys translating complex topics into actionable advice for both engineering and business teams

Understand and Optimize Your AWS Data Transfer Costs

Understand and Optimize Your AWS Data Transfer Costs

Data is one of your business’s most valuable assets and cloud infrastructure provides the access and flexibility needed to unlock its value. While it’s easy to quickly move data around in the cloud, each data transfer costs money and these costs and quickly add up over time if you’re not careful.

Let’s take a closer look at how to understand and optimize your AWS data transfer costs.

It’s easy to move data around in the cloud, but data transfer costs can quickly add up if you’re not careful!

On-Premise vs. Cloud

Data transfer costs are virtually non-existent for on-premise data centers. Once you setup a web server and storage server, there’s no cost to transfer data between them. The trade-off is that you need to invest in infrastructure upfront, hire a team to run it, and pay for any upgrades or maintenance costs.

Cloud infrastructure providers, such as Amazon AWS, help you avoid these setup and maintenance costs in exchange for usage and data transfer fees. In fact, data transfer costs represent a large portion of total AWS expenses for deployments with significant amounts of network traffic.

System administrators should pay close attention to the factors that influence data transfer in AWS environments and carefully monitor these costs to ensure that they don’t go out of control. Oftentimes, these data transfer costs must be weighed against the importance of security and availability.

Data Transfer in AWS

Amazon AWS charges for data transfers between AWS and the internet and between various AWS services, such as EC2 and S3. These charges may be included in the cost of the service, assessed in only one direction or assessed in both directions. It’s important to understand these variables to manage costs.


Download our Guide to Tracking Data Transfer Costs in Cost Explorer to learn how to setup filters in CostExplorer to track your data transfer costs in more detail.


AWS Data Transfer Costs - Source: Open Guides

In general, data transfer costs are highest for data transfers between regions, followed by data transfers between availability zones (AZs), and finally, within a single AZ. The AWS Open Guide provides a helpful visualization showing the dynamic nature of these costs, although it hasn’t been updated since August 2017 and may be outdated in areas.

How to Optimize Costs

Data transfer cost optimization is often a balance between stability, security, and cost. Resources split across regions, AZs, and VPCs certainly increase data transfer costs, but splitting resources also provides greater security and higher availability during disasters and outages.

The good news is a handful of best practices apply to all situations:

  • Efficient Routes: Minimize traffic between regions and AZs and maximize the traffic that stays within AZs since the costs tend to be significantly lower. If you don’t need high-cost regions, cut them to save on data transfer costs.
  • Avoid Public IPs: Data transfer costs are higher with public IP or elastic IP addresses compared to private addresses. If you’re only accessing data locally, use private addresses.
  • Look for Free Transfers: Some AWS services provide free cross-AZ data transfers, such as EFS, RDS, and MSK, which could make them a compelling option.
  • Use CloudFront: Amazon CloudFront is a global content delivery network (CDN) with free data transfers. If you have high data volumes, consider using it to keep costs down.
  • DIY NAT Instances: The high cost of managed NAT gateways, in data transfer and processing fees, means that it might make sense to run your own NAT instances to save on cost.
  • Experiment with Options: The AWS Simple Monthly Calculator lets you experiment with different configurations and learn how to maximize your savings. The data transfer section provides insight into data cost management.

By keeping these best practices in mind, you can minimize your data transfer costs while ensuring that security and availability aren’t adversely affected.

Creating Cost Awareness

Data transfer costs should be just one part of a larger effort to understand and control costs. With leaner corporate budgets following the COVID-19 outbreak, it’s important for everyone in an organization to take ownership of costs to help keep them under control — including both finance executives and engineering teams.

The process starts with effectively understanding costs and trends over time. AWS Cost Explorer provides access to much of this data, but CloudForecast can help instantly convert the raw data into digestible and actionable information for both business and engineering teams that are short on time.

After understanding these costs, it’s easier to identify ways to save with AWS Savings Plans, Spot Instances, and other tools. Engineering teams may also be able to identify unused instances and other instant cost savings opportunities, as well as scale up or down resources depending on demand at any given point in time.

How to Track Costs

AWS Cost Explorer lets you analyze data transfer costs for each instance as long as you enable cost allocation tags. You can analyze everything from data transfer costs as an aggregate number for regions, AZs, and virtual private clouds (VPCs) to data transfer costs on a per-application or per-instance basis.

CloudForecast’s Monthly Financial Report

CloudForecast eliminates the need to pull data, build and design reports to explain data transfer cost anomalies to finance and C-level executives. You can easily generate high-level cost reports each month in convenient Microsoft Excel formats designed for the intended audience.

Sign up for CloudForecast to get started today!

The Bottom Line

Cloud infrastructure providers may be cheaper than on-premise infrastructure on the surface, but there are several gotchas where costs can add up — including data transfer costs. By carefully monitoring your costs and adhering to some best practices, you can keep these costs well under control.

Sign up for CloudForecast today to monitor your AWS data transfer costs and other costs through daily engineering reports and monthly executive reports.