Isn't it expensive in terms of egress?

donavanm · on April 10, 2021

I'm not sure what you're specifically referring to by egress, but data transfer from S3/EC2/ELB etc to CloudFront is free:

> If you are using an AWS origin, effective December 1, 2014, data transferred from origin to edge locations (Amazon CloudFront "origin fetches") will be free of charge.

And in general data out from CloudFront ($0.085 to $0.02 in NA & EU) is cheaper than data out from S3 ($0.09 to $0.05 in us-east-2). For the lambda@Edge portion it's $0.60 per 1 million requests while the CloudFront requests are $0.75 to $1.00 per 1 million requests.

Those are public on demand rates and any customers with significant or consistent usage should definitely contact AWS for lower committed/custom prices.

Edit: Disclaimer I'm a principal at AWS, and in the past spent significant time working on CloudFront & Lambda@Edge, but all of the above is public information.