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Object Storage Service:Access OSS using transfer acceleration

Last Updated:Dec 08, 2025

Transfer acceleration provides end-to-end acceleration for long-distance uploads and downloads using a global network of data centers and smart routing. It resolves issues such as high latency and network instability during cross-region data transfers, which significantly improves transfer speeds and the user experience.

How it works

Transfer acceleration resolves the network latency and instability that can occur during long-distance access to Object Storage Service (OSS) using intelligent access point selection. When you access a bucket through an acceleration endpoint, the system automatically routes your request to the nearest Alibaba Cloud access point. The data then travels at high speed over Alibaba Cloud's optimized internal network to the region of the destination bucket.

By shortening the 'first mile' from the user to the Alibaba Cloud network, transfer acceleration avoids routing data over long and congested public internet paths. For example, consider a user in Beijing who wants to access an OSS bucket in Chengdu. A request to the bucket's public endpoint travels the entire distance over the complex, multi-hop public internet. In contrast, a request to the acceleration endpoint connects the user to a local Alibaba Cloud access point in Beijing. The data then travels directly to the bucket in Chengdu over Alibaba Cloud's dedicated global backbone network. This approach significantly reduces the transmission distance on the unstable public network, which improves transfer stability and speed.

Two types of acceleration endpoints are available to meet different compliance requirements:

  • Global acceleration endpoint: oss-accelerate.aliyuncs.com. This endpoint enables intelligent acceleration across all regions.

  • Acceleration endpoint for regions outside the Chinese mainland: oss-accelerate-overseas.aliyuncs.com. This endpoint uses access points located outside the Chinese mainland. You can use this endpoint when you map a domain that does not have an ICP filing to a bucket in the China (Hong Kong) region or another region outside the Chinese mainland using a CNAME record.

Enable access through transfer acceleration

Step 1: Enable transfer acceleration

After you enable transfer acceleration, the original endpoints of the bucket, such as the public endpoint, remain fully functional. This allows your application to choose the optimal access method based on the user's location and network conditions.

  1. Go to the Buckets page and click the name of the target bucket.

  2. In the navigation pane on the left, choose Bucket Settings > Transfer Acceleration.

  3. To the right of Enable Transfer Acceleration, turn on the switch. In the dialog box that appears, read the prompt and then click OK.

Step 2: Verify access

Choose a verification method based on the Access Control List (ACL) settings of the bucket.

Public-read or public-read-write buckets

You can access the object directly in a browser using its URL. For example, https://example-bucket.oss-accelerate.aliyuncs.com/dest.jpg is used to access the dest.jpg file in the example-bucket bucket.

Private buckets

To access an object in a private bucket, you must include signature information in the object URL. The following steps describe how to obtain a signed URL for an object from the OSS console. For more information about how to generate signatures, see Signature Version 4 (recommended).

  1. Go to the Buckets page and click the name of the target bucket.

  2. In the Actions column for the target object, click Details.

  3. Click Copy File URL and replace the public endpoint in the URL with the acceleration endpoint.

  4. Access the modified URL in your browser.

Step 3: Test the performance

The following test compares the download speed of an object from a bucket in the China (Hangzhou) region to an ECS instance in the Japan (Tokyo) region using ossutil.

Before you begin, install and configure ossutil 2.0.
  • Without acceleration

    ossutil cp oss://example-bucket/ossutil-2.1.2-mac-arm64.zip ossutil-2.1.2-mac-arm64.zip -e oss-cn-hangzhou.aliyuncs.com

    The download time is as follows:

    Success: Total 1 object, size 9281195 B, Download done:(1 files, 9281195 B), avg 8.733 MiB/s
    
    1.013983(s) elapsed
  • Enable Acceleration

    ossutil cp oss://example-bucket/ossutil-2.1.2-mac-arm64.zip ossutil-2.1.2-mac-arm64.zip -e oss-accelerate.aliyuncs.com

    The download time is described as follows:

    Success: Total 1 object, size 9281195 B, Download done:(1 files, 9281195 B), avg 20.155 MiB/s
    
    0.440160(s) elapsed

Apply in production

Best practices

  • Combine CDN with transfer acceleration: A multilayer acceleration architecture

    You can configure both CDN acceleration and transfer acceleration at the same time. By setting the CDN origin to the acceleration endpoint, you can create a multilayer acceleration system that combines CDN edge caching with transfer acceleration. The CDN serves user requests from the nearest cache, and transfer acceleration optimizes the CDN's origin-fetch path. This architecture is ideal for globally distributed static assets because it achieves full-path optimization for both cache hits and origin fetches.

  • Optimize large file transfers: Combine multipart transfer with acceleration

    To transfer gigabyte- or terabyte-scale files over long distances, you can combine transfer acceleration with multipart upload and resumable download. Transfer acceleration optimizes the quality of the network path, and multipart operations improve concurrency and fault tolerance. Together, these features significantly reduce the risk of timeouts and increase overall transfer efficiency.

  • Cost optimization: Implement a smart endpoint selection strategy

    You can implement an endpoint strategy that is tailored to different user groups and access scenarios. For users in the same region or with good network conditions, you can use the public endpoint to save on acceleration costs. For cross-region users or those with poor network quality, you can use the acceleration endpoint to improve their experience. We recommend that you develop an endpoint selection strategy based on your user distribution, business criticality, and cost budget.

Fault tolerance strategies

  • Domain Name Degradation

    Your application should include an endpoint fallback mechanism that automatically switches to the public endpoint if the acceleration endpoint becomes unavailable. This ensures business continuity. Transfer acceleration and the public endpoint are independent of each other. A failure in one does not affect the other, which provides redundancy for your application.

  • Handling list operations

    The acceleration endpoint supports only third-level domain access that includes the bucket name. Therefore, the acceleration endpoint cannot be used to list buckets. You must use the public endpoint for management operations, such as listing buckets, and the acceleration endpoint for data operations, such as uploads and downloads. This approach separates management traffic from data traffic.

Quotas and limitations

  • Protocol support: The acceleration endpoint supports API access only over HTTP and HTTPS. Non-HTTP or non-HTTPS protocols, such as RTMP, are not supported.

  • Propagation time: Changes to enable or disable transfer acceleration take up to 30 minutes to propagate across the entire network.

  • Secure transmission: To ensure data security, the backend might use HTTPS for internal data transmission. Therefore, if a client requests a file over HTTP, the access log might still record the request as an HTTPS request.

Billing

When you access OSS using transfer acceleration, you are charged for accelerated upload traffic and accelerated download traffic. For more information, see Transfer acceleration fees.