Amazon OpenSearch Serverless now supports Zstandard (zstd) codec for index compression

Posted on: Apr 9, 2026

Amazon OpenSearch Serverless now supports Zstandard codecs for index storage, giving customers greater control over the trade-off between storage costs and query performance. With this launch, customers can configure Zstandard compression to achieve up to 32% reduction in index size compared to the default LZ4 codec, helping lower managed storage costs for data-intensive workloads.

Customers running large-scale log analytics, observability pipelines, and time-series workloads on Amazon OpenSearch Serverless can benefit most from Zstandard compression where high data volumes make storage efficiency a significant cost driver. The Zstandard compression algorithm is available in two different modes in Amazon OpenSearch Serverless: zstd and zstd_no_dict. Customers can tune the compression level to balance their specific needs: lower levels (e.g., level 1) deliver meaningful storage savings with minimal impact on indexing throughput and query latency, while higher levels (e.g., level 6) maximize compression ratios at the cost of slower indexing speeds. 

Zstandard codec support is available today in all AWS Regions where Amazon OpenSearch Serverless is supported. To get started, you can specify these codecs in your index settings at creation time. For more information, see the Amazon OpenSearch Serverless documentation.