---
title: "S3 Trailing Checksums"
slug: "s3-trailing-checksums"
updated: 2026-10-27T17:23:57Z
published: 2026-10-27T17:23:57Z
canonical: "docs.vastdata.com/s3-trailing-checksums"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# S3 Trailing Checksums

VAST Cluster supports [S3 trailing checksums](https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html#trailing-checksums) introduced with the `x-amz-trailer` header.

if an S3 requests includes a checksum, the checksum is recognized as such and handled separately from the uploaded content.

> [!NOTE]
> Note
> 
> VAST Cluster does not perform checksum verification.

The CRC32C checksum algorithm is supported.

S3 trailing checksums can be recognized in the following S3 requests:

- PutObject
- PutObjectAcl
- PutObjectTagging
- PutObjectRetention
- PutObjectLegalHold
- CopyObject
- UploadPart
- CreateMultipartUpload
- PutBucketVersioning
- PutBucketTagging
- PutBucketPolicy
- PutBucketAcl
- PutBucketLifecycle
- PutBucketLifecycleConfig