Optional
AcceptOptional
ArchiveThe archive state of the head object.
This functionality is not supported for directory buckets.
Optional
BucketIndicates whether the object uses an S3 Bucket Key for server-side encryption with Key Management Service (KMS) keys (SSE-KMS).
This functionality is not supported for directory buckets.
Optional
CacheSpecifies caching behavior along the request/reply chain.
Optional
ChecksumCRC32The base64-encoded, 32-bit CRC32 checksum of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
Optional
ChecksumCRC32CThe base64-encoded, 32-bit CRC32C checksum of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
Optional
ChecksumSHA1The base64-encoded, 160-bit SHA-1 digest of the object. This will only be present if it was uploaded with the object. When you use the API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
Optional
ChecksumSHA256The base64-encoded, 256-bit SHA-256 digest of the object. This will only be present if it was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.
Optional
ContentSpecifies presentational information for the object.
Optional
ContentIndicates what content encodings have been applied to the object and thus what decoding mechanisms must be applied to obtain the media-type referenced by the Content-Type header field.
Optional
ContentThe language the content is in.
Optional
ContentSize of the body in bytes.
Optional
ContentA standard MIME type describing the format of the object data.
Optional
DeleteSpecifies whether the object retrieved was (true) or was not (false) a Delete Marker. If false, this response header does not appear in the response.
This functionality is not supported for directory buckets.
Optional
ETagAn entity tag (ETag) is an opaque identifier assigned by a web server to a specific version of a resource found at a URL.
Optional
ExpirationIf the object expiration is configured (see
PutBucketLifecycleConfiguration
), the response includes
this header. It includes the expiry-date
and rule-id
key-value
pairs providing object expiration information. The value of the rule-id
is
URL-encoded.
This functionality is not supported for directory buckets.
Optional
ExpiresOptional
ExpiresThe date and time at which the object is no longer cacheable.
Optional
LastDate and time when the object was last modified.
Optional
MetadataA map of metadata to store with the object in S3.
Optional
MissingThis is set to the number of metadata entries not returned in x-amz-meta
headers. This can happen if you create metadata using an API like SOAP that supports more
flexible metadata than the REST API. For example, using SOAP, you can create metadata whose
values are not legal HTTP headers.
This functionality is not supported for directory buckets.
Optional
ObjectSpecifies whether a legal hold is in effect for this object. This header is only
returned if the requester has the s3:GetObjectLegalHold
permission. This
header is not returned if the specified version of this object has never had a legal hold
applied. For more information about S3 Object Lock, see Object Lock.
This functionality is not supported for directory buckets.
Optional
ObjectThe Object Lock mode, if any, that's in effect for this object. This header is only
returned if the requester has the s3:GetObjectRetention
permission. For more
information about S3 Object Lock, see Object Lock.
This functionality is not supported for directory buckets.
Optional
ObjectThe date and time when the Object Lock retention period expires. This header is only
returned if the requester has the s3:GetObjectRetention
permission.
This functionality is not supported for directory buckets.
Optional
PartsThe count of parts this object has. This value is only returned if you specify
partNumber
in your request and the object was uploaded as a multipart
upload.
Optional
ReplicationAmazon S3 can return this header if your request involves a bucket that is either a source or a destination in a replication rule.
In replication, you have a source bucket on which you configure replication and
destination bucket or buckets where Amazon S3 stores object replicas. When you request an object
(GetObject
) or object metadata (HeadObject
) from these
buckets, Amazon S3 will return the x-amz-replication-status
header in the response
as follows:
If requesting an object from the source bucket,
Amazon S3 will return the x-amz-replication-status
header if the object in
your request is eligible for replication.
For example, suppose that in your replication configuration, you specify object
prefix TaxDocs
requesting Amazon S3 to replicate objects with key prefix
TaxDocs
. Any objects you upload with this key name prefix, for
example TaxDocs/document1.pdf
, are eligible for replication. For any
object request with this key name prefix, Amazon S3 will return the
x-amz-replication-status
header with value PENDING, COMPLETED or
FAILED indicating object replication status.
If requesting an object from a destination
bucket, Amazon S3 will return the x-amz-replication-status
header
with value REPLICA if the object in your request is a replica that Amazon S3 created and
there is no replica modification replication in progress.
When replicating objects to multiple destination
buckets, the x-amz-replication-status
header acts
differently. The header of the source object will only return a value of COMPLETED
when replication is successful to all destinations. The header will remain at value
PENDING until replication has completed for all destinations. If one or more
destinations fails replication the header will return FAILED.
For more information, see Replication.
This functionality is not supported for directory buckets.
Optional
RequestIf present, indicates that the requester was successfully charged for the request.
This functionality is not supported for directory buckets.
Optional
RestoreIf the object is an archived object (an object whose storage class is GLACIER), the response includes this header if either the archive restoration is in progress (see RestoreObject or an archive copy is already restored.
If an archive copy is already restored, the header value indicates when Amazon S3 is scheduled to delete the object copy. For example:
x-amz-restore: ongoing-request="false", expiry-date="Fri, 21 Dec 2012 00:00:00
GMT"
If the object restoration is in progress, the header returns the value
ongoing-request="true"
.
For more information about archiving objects, see Transitioning Objects: General Considerations.
This functionality is not supported for directory buckets. Only the S3 Express One Zone storage class is supported by directory buckets to store objects.
Optional
SSECustomerIf server-side encryption with a customer-provided encryption key was requested, the response will include this header to confirm the encryption algorithm that's used.
This functionality is not supported for directory buckets.
Optional
SSECustomerIf server-side encryption with a customer-provided encryption key was requested, the response will include this header to provide the round-trip message integrity verification of the customer-provided encryption key.
This functionality is not supported for directory buckets.
Optional
SSEKMSKeyIf present, indicates the ID of the Key Management Service (KMS) symmetric encryption customer managed key that was used for the object.
This functionality is not supported for directory buckets.
Optional
ServerThe server-side encryption algorithm used when you store this object in Amazon S3 (for example,
AES256
, aws:kms
, aws:kms:dsse
).
For directory buckets, only server-side encryption with Amazon S3 managed keys (SSE-S3) (AES256
) is supported.
Optional
StorageProvides storage class information of the object. Amazon S3 returns this header for all objects except for S3 Standard storage class objects.
For more information, see Storage Classes.
Directory buckets - Only the S3 Express One Zone storage class is supported by directory buckets to store objects.
Optional
VersionVersion ID of the object.
This functionality is not supported for directory buckets.
Optional
WebsiteIf the bucket is configured as a website, redirects requests for this object to another object in the same bucket or to an external URL. Amazon S3 stores the value of this header in the object metadata.
This functionality is not supported for directory buckets.
Indicates that a range of bytes was specified.