data transfer
15 articles on data transfer — what drives the cost, how it is priced, and where the savings actually are.
Cross-AZ vs cross-region data transfer cost: the two hidden network taxes
Traffic between availability zones costs about $0.01 per GB each way, while traffic between regions runs roughly $0.02 per GB or more. Both are easy to trigger accidentally and both compound at scale. Here is how the two taxes differ and how to avoid them.
Private IP vs public IP data transfer cost: the free path you might be missing
Traffic between resources over private IPs in the same AZ is free, but the same traffic over public or Elastic IPs is charged even within a region. Using the wrong address turns free traffic into a per-GB bill. Here is how to keep it free.
Egress cost reduction checklist: cutting the data transfer bill
Data egress (traffic leaving AWS to the internet, and between regions and AZs) is one of the most surprising and controllable line items. This checklist walks through the highest-impact ways to cut it, from CDN caching to architecture.
Inter-AZ data transfer cost: the charge hiding inside your VPC
Traffic between availability zones inside the same region is not free. At roughly a cent per GB in each direction, cross-AZ transfer quietly adds up for chatty microservices, replicated databases, and Kafka clusters. Here is how it is billed and how to cut it.
Are cloud data transfers free? The rules that decide
Some cloud data transfers are free (inbound, same-AZ private traffic) and some are expensive (egress to the internet, cross-region, cross-AZ). Knowing which is which is essential to avoiding surprise bills. Here is the map.
Cloud CDN cost compared: CloudFront, Cloud CDN, and Azure CDN
A content delivery network bills mostly for data transfer out and requests, and the rates vary by provider and region. Here is how CloudFront, Google Cloud CDN, and Azure CDN compare, and how to keep CDN cost predictable.
Cross-region replication cost: what copying data between regions really costs
Replicating data across regions for durability or latency adds cross-region data transfer charges plus duplicated storage, and the transfer is often the bigger surprise. Here is how cross-region replication is priced and how to control it.
Data transfer out cost explained: the cloud's most surprising charge
Data transfer out, egress to the internet, is one of the least understood and most surprising cloud charges. Inbound is usually free, outbound is not, and it scales with traffic and region. Here is how egress pricing works and how to cut it.
Image optimization: cutting storage and egress with smaller files
Images are often the largest bytes a site serves, so optimizing them, right-sizing dimensions, modern formats like WebP and AVIF, and compression, cuts egress and storage substantially. Here is where image optimization saves cloud cost.
Compression to reduce cloud cost: fewer bytes, lower bills
Compression shrinks the bytes you store, transfer, and scan, and cloud bills those bytes. Compressing data can cut storage, egress, and query cost at once, for a little CPU. Here is where compression pays and where it does not.
Data transfer cost across clouds: the line item that varies most
Compute and storage have converged, but data transfer hasn't. Here's the shared structure (ingress free, egress tiered, cross-region charged), where AWS/Azure/GCP diverge, and the universal levers to cut it.
Azure egress bandwidth cost: first 100 GB free, then it adds up
Azure egress is free for the first 100 GB/month, then tiered ~$0.087/GB; ingress is free. Here's the egress map, the patterns that drive the bill, and how a CDN and region co-location cut it.
Azure VNet peering cost: the per-GB charge that bills both ways
VNet peering has no hourly fee but charges ~$0.01/GB each direction (more for global). It bills on both sides. Here's where the cost hides in hub-and-spoke and chatty services, and how to cut it.
GCP network egress cost explained: ingress is free, everything out costs
GCP charges for egress to the internet, between regions, and even between zones, but not ingress or same-zone traffic. Here's the egress map, the three patterns that drive the bill, and how to cut it.
AWS data transfer costs explained
The most opaque part of the AWS bill, broken down. Internet egress, cross-region, cross-AZ, NAT processing, CloudFront, VPC endpoints. The five biggest cost surprises and how to fix them.