How to reduce Data Transfer Cost in AWS

We have a number of available resources that can help you understand network data transfer usage and charges better, explain which tools you could use to visualize them, and also optimize it.

Depending which services you use, and how your services connect and share the traffic, you might want to check some of these blogposts:

• Overview of Data Transfer Costs for Common Architectures
• Exploring Data Transfer Costs for AWS Managed Databases
• Using AWS Cost Explorer to analyze data transfer costs
• How can I reduce data transfer charges for my NAT gateway?

Also, take a look at this video presentatino with the demo from AWS Supports You twitch series on how to monitor and tips how to optimize data transfer costs: AWS Supports You | Monitoring and Optimizing Your Data Transfer Costs

From your screenshot it looks like the majority of your data transfer charges are related to the traffic that goes from your resources and then leaving AWS (traffic going Out to the Internet). Depending on your setup, you could evaluate if it's worth using CloudFront, if your traffic goes to end users who access data from your resources over the Internet. Also, with CloudFront, you would use the security savings bundle, and save up to 30% on your CF usage if you plan to grow your usage over time.

There is some guidance provided here - https://docs.aws.amazon.com/wellarchitected/latest/cost-optimization-pillar/plan-for-data-transfer.html