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Upload Part


The Upload Part operation uploads a part in a multipart upload for an object.

Supported request headers

The following request headers are supported:

  • Content-Length

  • Content-MD5

Request headers for server-side encryption

If you specified SSE-C encryption for the Initiate Multipart Upload request, you must also include the following request headers in each Upload Part request:

  • x-amz-server-side-encryption-customer-algorithm: Specify AES256.

  • x-amz-server-side-encryption-customer-key: Specify the same encryption key that you provided in the Initiate Multipart Upload request.

  • x-amz-server-side-encryption-customer-key-MD5: Specify the same MD5 digest that you provided in the Initiate Multipart Upload request.

Important The encryption keys you provide are never stored. If you lose an encryption key, you lose the corresponding object. Before using customer-provided keys to secure object data, review the considerations in “Use server-side encryption.”


Multipart upload consists of separate operations for initiating the upload, listing uploads, uploading parts, assembling the uploaded parts, and completing the upload. Objects are created (and versioned if applicable) when the Complete Multipart Upload operation is performed.

Related information

Use server-side encryption