Versioning for Azure Storage

Azure Storage supports multiple versions. To make a request against the storage services, you must specify the version that you want to use for that operation, unless the request is anonymous.

As of April 30, 2025, the latest fully deployed version of the Azure Storage service is 2025-05-05. 2025-07-05 is also broadly deployed, as indicated in the table below. All three versions are GA quality.

Note that if the table indicates an x-ms-version is enabled in a region, all previous x-ms-versions are also enabled. If you attempt to use a service version that is not fully deployed in the region where your storage account resides, you may encounter an x-ms-version mismatch error.

The default x-ms-version being used by the Azure Storage data plane SDKs can be found in the changelogs in the table below:

The latest version of the Azure storage services is 2025-07-05, and we recommend that you use it where possible. For a list of all other supported versions, and for information about using each version, see Previous Azure Storage service versions.

The 2025-07-05 service version includes the following features:

• Added support for the x-ms-file-request-intent request header to the following APIs: Put Blob from URL, Copy Blob from URL, Put Block from URL, Put Page from URL, and Append Block from URL.
• Added support for the Create Symbolic Link and Read Symbolic Link APIs. Note that these APIs are only applicable to NFS Shares in premium file storage accounts.

Specify service versions in requests

How you specify the version of the storage services to use for a request relates to how that request is authorized. The following sections describe authorization options and how the service version is specified for each.

• Requests that use an OAuth 2.0 token from Microsoft Entra: To authorize a request with Microsoft Entra ID, pass the x-ms-version header on the request with a service version of 2017-11-09 or higher. For more information, see Call storage operations with OAuth tokens in Authorize with Microsoft Entra ID.

• Requests that use Shared Key or Shared Key Lite: To authorize a request with Shared Key or Shared Key Lite, pass the x-ms-version header on the request. In the case of Azure Blob Storage, you can specify the default version for all requests by calling Set Blob Service Properties.

• Requests that use a shared access signature (SAS): You can specify two versioning options on a shared access signature. The optional api-version header indicates which service version to use to execute the API operation. The required SignedVersion (sv) parameter specifies the service version to use to authorize the request made with the SAS. If the api-version header isn't specified, the value of the SignedVersion (sv) parameter also indicates the version to use to execute the API operation.

• Requests that use anonymous access: In the case of anonymous access against Blob Storage, no version is passed in. The heuristics for determining which version to use for the request are described in the next sections.

Authorize requests by using Microsoft Entra ID, Shared Key, or Shared Key Lite

To authorize a request with Microsoft Entra ID, Shared Key, or Shared Key Lite, specify the x-ms-version header on the request. The x-ms-version request header value must be specified in the format YYYY-MM-DD. For example:

Request Headers:  
x-ms-version: 2020-04-08

The following rules describe how these requests are evaluated to determine which version to use to process the request.

• If a request has a valid x-ms-version header, the storage service uses the specified version. All requests to Azure Table Storage and Azure Queue Storage that don't use a shared access signature must specify an x-ms-version header. All requests to Blob Storage that don't use a shared access signature must specify an x-ms-version header unless the default version has been set, as described in the next paragraph.

• If a request to Blob Storage doesn't have an x-ms-version header, but the account owner has set a default version by using the Set Blob Service Properties operation, the specified default version is used as the version for the request.

Authorize requests by using a shared access signature

A shared access signature (SAS) that's generated by using version 2014-02-14 or later supports two versioning options:

• The api-version query parameter defines the REST protocol version to use for processing a request that's made by using the SAS.

• The SignedVersion (sv) query parameter defines the SAS version to use for authorization.

The SignedVersion query parameter is used for authorization when a client makes a request by using the SAS. Authorization parameters such as si, sr, sp, sig, st, se, tn, spk, srk, epk, and erk are all interpreted by using the specified version.

REST protocol parameters such as rscc, rscd, rsce, rscl, and rsct are enforced by using the version that's provided in the api-version parameter header. If the api-version header isn't specified, the service version that's provided for SignedVersion is used.

The api-version parameter isn't part of the string-to-sign in the authorization header, as described in Create a service SAS.

The following table explains the versioning scheme that's used by the service for authorization and for calling the REST protocol when the SignedVersion parameter is set to version 2014-02-14 or later.

Example 1

The following sample request calls List Blobs with sv=2015-04-05, and without the api-version parameter.

https://myaccount.blob.core.windows.net/mycontainer?restype=container&comp=list&sv=2015-04-05&si=readpolicy&sig=a39 %2BYozJhGp6miujGymjRpN8tsrQfLo9Z3i8IRyIpnQ%3d

In this case, the service authenticates and authorizes the request by using version 2015-04-05, and it runs the operation by using version 2015-04-05.

Example 2

The following sample request calls List Blobs with sv=2015-04-05 and with the api-version parameter.

https://myaccount.blob.core.windows.net/mycontainer?restype=container&comp=list&sv=2015-04-05&si=readpolicy&sig=a39 %2BYozJhGp6miujGymjRpN8tsrQfLo9Z3i8IRyIpnQ%3d&api-version=2012-02-12

Here, the service authorizes the request by using version 2015-04-05, and it runs the operation by using version 2012-02-12.

Requests via anonymous access

Requests that are made via anonymous access are handled differently, depending on the type of storage account they're made against.

For general-purpose storage accounts

If an anonymous request to a general-purpose storage account doesn't specify the x-ms-version header, and the default version for the service hasn't been set by using Set Blob Service Properties, the service uses the earliest possible version to process the request. However, if the container was made public with a Set Container ACL operation that was performed by using version 2009-09-19 or later, the request is processed by using version 2009-09-19.

For Blob Storage accounts

If an anonymous request to a Blob Storage account doesn't specify the x-ms-version header, and the default version for the service hasn't been set by using Set Blob Service Properties, the service uses the earliest possible version to process the request. For a Blob Storage account, the earliest possible version is 2014-02-14.

Known issues

This section details known issues for the Azure Storage REST APIs.

InvalidHeaderValue error message

In rare scenarios, applications making direct REST API calls can receive an InvalidHeaderValue error message. The error looks similar to the following sample:

HTTP/1.1 400 The value for one of the HTTP headers is not in the correct format.
Content-Length: 328
Content-Type: application/xml
Server: Microsoft-HTTPAPI/2.0
x-ms-request-id: <REMOVED>
Date: Fri, 19 May 2023 17:10:33 GMT
 
<?xml version="1.0" encoding="utf-8"?><Error><Code>InvalidHeaderValue</Code><Message>The value for one of the HTTP headers is not in the correct format.
RequestId:<REMOVED>
Time:2023-05-19T17:10:34.2972651Z</Message><HeaderName>x-ms-version</HeaderName><HeaderValue>yyyy-mm-dd</HeaderValue></Error> 

It's recommended that you use an earlier REST API version to see if the issue resolves. If the issue persists, or if the recommendation is not feasible, please open a support ticket to discuss further options.

See also

• Storage Services REST
• Versioning best practices
• Protocol version support for .NET client library versions