Support for Alternative Compression Methods (e.g., zstd) for Load Balancer Logs?

Question

By default, AWS load balancers (both ELB and ALB) store their connection and access logs in S3 using gzip compression. I’m considering the potential benefits of using a compression algorithm such as zstd, which offers a higher compression ratio. Such a change could improve compatibility with Athena queries and further reduce S3 storage costs.

Currently, it appears that only gzip is supported natively. While one could implement a solution (e.g., using Lambda to decompress gzip files and recompress them using zstd) to achieve this, that approach would incur additional operational costs.

**My questions are:**  
- Is there any native support or configuration option to choose an alternative compression algorithm (like zstd) for load balancer logs directly at the time of storage?  
- Are there any plans to support alternative compression methods in the future to optimize storage costs and Athena query performance?

Riku_Kobayashi · Answer

Hello.

> Is there any native support or configuration option to choose an alternative compression algorithm (like zstd) for load balancer logs directly at the time of storage?

There is no setting in ALB to change the compression method for ALB access logs to a different one.  
As you are aware, currently it is not possible to change from gzip compression unless you use Lambda or Glue etc.  
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-access-logs.html

> Are there any plans to support alternative compression methods in the future to optimize storage costs and Athena query performance?

I'm not an AWS employee so I don't know what the future roadmap is.  
If your AWS account has an AWS Support Developer Plan or higher, you may want to consider making a feature request.  
https://docs.aws.amazon.com/awssupport/latest/user/case-management.html#choosing-severity

Raj Koli · Answer

Hello,

1. Is there any native support or configuration option to choose an alternative compression algorithm (like zstd) for load balancer logs directly at the time of storage ?  
Unfortunately, there is no native support or configuration option to choose alternative compression algorithms for AWS Load Balancer logs. Currently, gzip is the only supported compression format, and this is hardcoded into the ELB/ALB logging functionality. You cannot modify this at the time of storage.

2. Are there any plans to support alternative compression methods in the future to optimize storage costs and Athena query performance ?  
As of April 2025, AWS has not publicly announced any plans to support alternative compression methods for load balancer logs. While AWS has adopted zstd in other services like Redshift, there have been no indications or announcements about implementing additional compression options for load balancer logging.

I have raised a feature request on your behalf. This will help ensure that your feedback is taken into consideration by the development team. Thank you for bringing this to our attention.

I suggest keeping an eye on the following sites [1] [2] for AWS releases and announcements regarding updates to this feature.

##### Reference:

[1] https://aws.amazon.com/new/   
[2] https://aws.amazon.com/blogs/aws/

Support for Alternative Compression Methods (e.g., zstd) for Load Balancer Logs?

Reference:

Relevant content