Copy Blob From URL

The Copy Blob From URL operation copies a blob to a destination within the storage account synchronously for source blob sizes up to 256 mebibytes (MiB). This API is available starting in version 2018-03-28.

The source for a Copy Blob From URL operation can be any committed block blob in any Azure storage account that's either public or authorized with a shared access signature.

Request

You can construct the Copy Blob From URL request as follows. We recommend HTTPS. Replace myaccount with the name of your storage account, mycontainer with the name of your container, and myblob with the name of your destination blob.

PUT method request URI HTTP version
https://myaccount.blob.core.windows.net/mycontainer/myblob HTTP/1.1

URI for the emulated storage service

When you're making a request against the emulated storage service, specify the emulator host name and Azure Blob Storage port as 127.0.0.1:10000, followed by the name of the emulated storage account:

PUT method request URI HTTP version
http://127.0.0.1:10000/devstoreaccount1/mycontainer/myblob HTTP/1.1

For more information, see Use the Azurite emulator for local Azure Storage development.

URI parameters

You can specify the following additional parameters on the request URI:

Parameter Description
timeout Optional. The timeout parameter is expressed in seconds. For more information, see Set timeouts for Blob Storage operations.

Request headers

The following table describes required and optional request headers:

Request header Description
Authorization Required. Specifies the authorization scheme, account name, and signature. For more information, see Authorize requests to Azure Storage.
Date or x-ms-date Required. Specifies the Coordinated Universal Time (UTC) for the request. For more information, see Authorize requests to Azure Storage.
x-ms-version Required for all authorized requests. For more information, see Versioning for the Azure Storage services.
x-ms-meta-name:value Optional. Specifies a user-defined name/value pair associated with the blob. If no name/value pairs are specified, the operation will copy the metadata from the source blob or file to the destination blob. If one or more name/value pairs are specified, the destination blob is created with the specified metadata, and metadata is not copied from the source blob or file.

Beginning with version 2009-09-19, metadata names must adhere to the naming rules for C# identifiers. For more information, see Naming and referencing containers, blobs, and metadata.
x-ms-encryption-scope Optional. Indicates the encryption scope for encrypting the request contents. This header is supported in version 2020-12-06 and later.
x-ms-tags Optional. Sets query-string-encoded tags on the blob. Tags are not copied from the copy source. For more information, see Remarks. Supported in version 2019-12-12 and later.
x-ms-copy-source-tag-option Optional. Possible values are REPLACE and COPY (case-sensitive). The default value is REPLACE.

If COPY is specified, the tags from the source blob will be copied to the destination blob. The source blob must be private, and the request must have permission to the Get Blob Tags operation on the source blob and the Set Blob Tags operation on the destination blob. This incurs an extra call to the Get Blob Tags operation on the source account.

REPLACE will set tags that the x-ms-tags header specifies on the destination blob. If x-ms-tags specifies REPLACE and no tags, then no tags will be set on the destination blob. Specifying COPY and x-ms-tags will result in a 409 (Conflict) error.

Supported in version 2021-04-10 and later.
x-ms-source-if-modified-since Optional. A DateTime value. Specify this conditional header to copy the blob only if the source blob has been modified since the specified date/time. If the source blob has not been modified, Blob Storage returns status code 412 (Precondition Failed). You can't specify this header if the source is an Azure file.
x-ms-source-if-unmodified-since Optional. A DateTime value. Specify this conditional header to copy the blob only if the source blob has not been modified since the specified date/time. If the source blob has been modified, Blob Storage returns status code 412 (Precondition Failed). You can't specify this header if the source is an Azure file.
x-ms-source-if-match Optional. An ETag value. Specify this conditional header to copy the source blob only if its ETag value matches the specified value. If the values don't match, Blob Storage returns status code 412 (Precondition Failed). You can't specify this header if the source is an Azure file.
x-ms-source-if-none-match Optional. An ETag value. Specify this conditional header to copy the blob only if its ETag value doesn't match the specified value. If the values are identical, Blob Storage returns status code 412 (Precondition Failed). You can't specify this header if the source is an Azure file.
If-Modified-Since Optional. A DateTime value. Specify this conditional header to copy the blob only if the destination blob has been modified since the specified date/time. If the destination blob has not been modified, Blob Storage returns status code 412 (Precondition Failed).
If-Unmodified-Since Optional. A DateTime value. Specify this conditional header to copy the blob only if the destination blob has not been modified since the specified date/time. If the destination blob has been modified, Blob Storage returns status code 412 (Precondition Failed).
If-Match Optional. An ETag value. Specify an ETag value for this conditional header to copy the blob only if the specified ETag value matches the ETag value for an existing destination blob. If the values don't match, Blob Storage returns status code 412 (Precondition Failed).
If-None-Match Optional. An ETag value, or the wildcard character (*).

Specify an ETag value for this conditional header to copy the blob only if the specified ETag value doesn't match the ETag value for the destination blob.

Specify the wildcard character (*) to perform the operation only if the destination blob doesn't exist.

If the specified condition isn't met, Blob Storage returns status code 412 (Precondition Failed).
x-ms-copy-source:name Required. Specifies the URL of the source blob. The value can be a URL of up to 2 kibibytes (KiB) in length that specifies a blob. The value should be URL-encoded as it would appear in a request URI. The source blob must either be public or be authorized via a shared access signature. If the source blob is public, no authorization is required to perform the operation. If the size of the source blob is greater than 256 MiB, the request fails with a 409 (Conflict) error. The blob type of the source blob has to be block blob. Here are some examples of source object URLs:

- https://myaccount.blob.core.windows.net/mycontainer/myblob
- https://myaccount.blob.core.windows.net/mycontainer/myblob?snapshot=<DateTime>
- https://myaccount.blob.core.windows.net/mycontainer/myblob?versionid=<DateTime>
x-ms-copy-source-authorization: <scheme> <signature> Optional. Specifies the authorization scheme and signature for the copy source. For more information, see Authorize requests to Azure Storage.
Only the scheme bearer is supported for Microsoft Entra.
This header is supported in version 2020-10-02 and later.
x-ms-requires-sync:true Required. Indicates that this is a synchronous Copy Blob From URL operation instead of an asynchronous Copy Blob operation.
x-ms-source-content-md5 Optional. Specifies an MD5 hash of the blob content from the URI. This hash is used to verify the integrity of the blob during transport of the data from the URI. When this header is specified, the storage service compares the hash of the content that has arrived from the copy source with this header value.

The MD5 hash is not stored with the blob.

If the two hashes don't match, the operation fails with error code 400 (Bad Request).
x-ms-lease-id:<ID> Required if the destination blob has an active lease. The lease ID specified for this header must match the lease ID of the destination blob. If the request doesn't include the lease ID or it isn't valid, the operation fails with status code 412 (Precondition Failed).

If this header is specified and the destination blob doesn't currently have an active lease, the operation fails with status code 412 (Precondition Failed).

In version 2012-02-12 and later, this value must specify an active, infinite lease for a leased blob. A finite-duration lease ID fails with status code 412 (Precondition Failed).
x-ms-client-request-id Optional. Provides a client-generated, opaque value with a 1-KiB character limit that's recorded in the logs when logging is configured. We highly recommend that you use this header to correlate client-side activities with requests that the server receives.
x-ms-access-tier Optional. Specifies the tier to be set on the target blob. This header is for page blobs on a premium account only with version 2017-04-17 and later. For a full list of supported tiers, see High-performance premium storage and managed disks for VMs. This header is supported on version 2018-11-09 and later for block blobs. Block blob tiering is supported on Blob Storage or General Purpose v2 accounts. Valid values are Hot, Cool, Cold, and Archive. Note: Cold tier is supported for version 2021-12-02 and later. For detailed information about block blob tiering, see Hot, cool, and archive storage tiers.

Request body

None.

Response

The response includes an HTTP status code and a set of response headers.

Status code

A successful operation returns status code 202 (Accepted).

For information about status codes, see Status and error codes.

Response headers

The response for this operation includes the following headers. The response might also include additional standard HTTP headers. All standard headers conform to the HTTP/1.1 protocol specification.

Response header Description
ETag If the copy is complete, contains the ETag value of the destination blob. If the copy isn't complete, contains the ETag value of the empty blob created at the start of the copy.

The ETag value is in quotation marks.
Last-Modified Returns the date/time that the copy operation to the destination blob finished.
x-ms-request-id Uniquely identifies the request that was made. You can use it to troubleshoot the request. For more information, see Troubleshoot API operations.
x-ms-version Indicates the version of Blob Storage that's used to execute the request.
Date A UTC date/time value that indicates the time at which the service sent the response.
x-ms-copy-id: <id> String identifier for this copy operation.
x-ms-copy-status: <success> Indicates the state of the copy operation. A value of success means that the operation finished successfully.
x-ms-client-request-id Can be used to troubleshoot requests and corresponding responses. The value of this header is equal to the value of the x-ms-client-request-id header, if it's present in the request and the value is at most 1,024 visible ASCII characters. If the x-ms-client-request-id header is not present in the request, this header won't be present in the response.
x-ms-request-server-encrypted: true/false Set to true if the contents of the request are successfully encrypted through the specified algorithm. Otherwise, the value is false.
x-ms-encryption-scope Returned if the request used an encryption scope, so the client can ensure that the contents of the request are successfully encrypted through the encryption scope.

Response body

None.

Sample response

The following is a sample response for a request to copy a blob:

Response Status:  
HTTP/1.1 202 Accepted  
  
Response Headers:   
Last-Modified: <date>   
ETag: "0x8CEB669D794AFE2"  
Server: Windows-Azure-Blob/1.0 Microsoft-HTTPAPI/2.0  
x-ms-request-id: cc6b209a-b593-4be1-a38a-dde7c106f402  
x-ms-version: 2018-03-28  
x-ms-copy-id: 1f812371-a41d-49e6-b123-f4b542e851c5  
x-ms-copy-status: success  
Date: <date>  
  

Authorization

Authorization is required when calling any data access operation in Azure Storage. The following table describes how the destination and source objects for a Copy Blob From URL operation can be authorized:

Object type Microsoft Entra ID authorization Shared Access Signature (SAS) authorization Shared Key authorization (or Shared Key Lite)
Destination block blob Yes Yes Yes
Source block blob in same storage account Yes Yes Yes
Source block blob in another storage account No Yes No

If a request specifies tags in the x-ms-tags request header, the caller must meet the authorization requirements of the Set Blob Tags operation.

You can authorize the Copy Blob From URL operation as described below. Note that a source blob in a different storage account must be authorized separately via SAS token with the Read (r) permission. For more information on source blob authorization, see the details for the request header x-ms-copy-source.

Important

Microsoft recommends using Microsoft Entra ID with managed identities to authorize requests to Azure Storage. Microsoft Entra ID provides superior security and ease of use compared to Shared Key authorization.

Azure Storage supports using Microsoft Entra ID to authorize requests to blob data. With Microsoft Entra ID, you can use Azure role-based access control (Azure RBAC) to grant permissions to a security principal. The security principal may be a user, group, application service principal, or Azure managed identity. The security principal is authenticated by Microsoft Entra ID to return an OAuth 2.0 token. The token can then be used to authorize a request against the Blob service.

To learn more about authorization using Microsoft Entra ID, see Authorize access to blobs using Microsoft Entra ID.

Permissions

Listed below are the RBAC action necessary for a Microsoft Entra user, group, managed identity, or service principal to call the Copy Blob From URL operation, and the least privileged built-in Azure RBAC role that includes this action:

Destination blob

Source blob within same storage account

To learn more about assigning roles using Azure RBAC, see Assign an Azure role for access to blob data.

Remarks

The source and destination blob for a Copy Blob From URL operation must be a block blob.

In version 2020-10-02 and later, Microsoft Entra authorization is supported for the source of the copy operation.

The Copy Blob From URL operation always copies the entire source blob. Copying a range of bytes or set of blocks is not supported.

You can copy a source blob to a destination blob that has a different name. The destination blob can be an existing block blob, or it can be a new blob that the copy operation creates.

When you're copying from a block blob, all committed blocks and their block IDs are copied. Uncommitted blocks are not copied. At the end of the copy operation, the destination blob will have the same committed block count as the source.

The ETag value for a block blob changes when the Copy Blob From URL operation starts and when the operation finishes.

Copying blob properties and metadata

When a block blob is copied, the following system properties are copied to the destination blob with the same values:

  • Content-Type

  • Content-Encoding

  • Content-Language

  • Content-Length

  • Cache-Control

  • Content-MD5

  • Content-Disposition

The source blob's committed block list is also copied to the destination blob. Any uncommitted blocks are not copied.

The destination blob is always the same size as the source blob, so the value of the Content-Length header for the destination blob matches the value of that header for the source blob.

If the x-ms-tags header provides tags for the destination blob, they must be query-string encoded. Tag keys and values must conform to the naming and length requirements specified in the Set Blob Tags operation.

The x-ms-tags header can contain up to 2 kilobits of tags. If you need more tags, use the Set Blob Tags operation.

If the x-ms-tags header doesn't provide tags, then tags aren't copied from the source blob.

Copying a leased blob

The Copy Blob From URL operation only reads from the source blob, so the lease state of the source blob doesn't matter.

Billing

Pricing requests can originate from clients that use Blob Storage APIs, either directly through the Blob Storage REST API, or from an Azure Storage client library. These requests accrue charges per transaction. The type of transaction affects how the account is charged. For example, read transactions accrue to a different billing category than write transactions. The following table shows the billing category for Copy Blob From URL requests based on the storage account type:

Operation Storage account type Billing category
Copy Blob From URL (destination account1) Premium block blob
Standard general-purpose v2
Standard general-purpose v1
Write operations
Copy Blob From URL (source account2) Premium block blob
Standard general-purpose v2
Standard general-purpose v1
Read operations

1The destination account is charged for one transaction to initiate the write.
2The source account incurs one transaction for each read request to the source object.

To learn about pricing for the specified billing categories, see Azure Blob Storage Pricing.

In addition, if the source and destination accounts reside in different regions (for example, US North and US South), bandwidth that you use to transfer the request is charged to the source storage account as egress. Egress between accounts within the same region is free.

When you copy a source blob to a destination blob that has a different name within the same account, you use additional storage resources for the new blob. The copy operation then results in a charge against the storage account's capacity usage for those additional resources.

See also

Authorize requests to Azure Storage
Status and error codes
Blob Storage error codes
Understanding how snapshots accrue charges