Revised Title: AWS Updates Pricing Policy for S3 API with Exemption on 3XX/4XX Responses from External Sources

AWS has announced a change in their billing policy for S3 API charges, following incidents where charges for empty buckets exceeded 50,000 baht per day for customers. They will now waive charges for responses in the form of redirection (HTTP 3XX) or errors (HTTP 4XX) originating from outside the customer’s network. However, if the error occurs when called from within the customer’s network, charges will continue to apply. This includes cases where S3 is used for web hosting, and custom errors or redirects are set up.

For responses indicating errors from the S3 side (HTTP 5XX), AWS will no longer charge. Regular responses with HTTP 200 will be billed in almost all cases.

All HTTP responses that will not incur charges for clients outside of the account include 301, 307, 200, 400, 403 (Access Denied, the primary response when external users attempt to send requests), 404, 405, 409, 411, and 412.

This policy took effect on May 13th but is still being deployed, so it may not be fully implemented in all regions yet. AWS plans to announce when the deployment is complete.

TLDR: AWS adjusts S3 API billing policy, waiving charges for certain error responses while continuing to bill for others, with changes effective from May 13th.