The old version of Image processing (IMG) uses dedicated IMG domain names and a separate URL format that limits access to HTTPS, Virtual Private Cloud (VPC), and Alibaba Cloud CDN cache refresh. The new version eliminates these restrictions by routing all operations — upload, management, processing, and distribution — through standard OSS domain names.
The old version of IMG is no longer updated. Use the new version. For setup instructions, see IMG implementation modes.
Compatibility at a glance
Before reviewing the technical differences, note the following compatibility boundaries:
Image styles are shared between versions — styles defined in the old version work in the new version without changes.
Old version API operations are not supported in the new version. If your application calls old version APIs directly, contact technical support by submitting a ticket before migrating.
Old version bucket configurations (such as source image protection) apply only to IMG domain names, not to OSS domain names — except when cross-region replication (CRR) is enabled, in which case they are synchronized to OSS domain names.
URL format
The two versions use different URL formats.
New version:
http://bucket.<endpoint>/object?x-oss-process=image/action,param_valuebucket.<endpoint>— the OSS domain name for the bucketx-oss-process=image/— the query parameter that triggers IMG processingaction,param_value— the processing action and its value (for example,resize,w_200)
Chain multiple processing actions within the x-oss-process parameter. OSS executes them sequentially.
Old version:
http://channel.<endpoint>/object@action.formatchannel.<endpoint>— a dedicated IMG subdomain (old version only)@action.format— processing actions specified after the@delimiter
Domain name comparison
The old version uses dedicated IMG domain names. The new version uses OSS domain names for all operations.
| Feature | IMG domain names (old version) | OSS domain names (new version) |
|---|---|---|
| Access method | OSS domain names for storage + IMG domain names for processing | OSS domain names for upload, management, processing, and distribution |
| New version API operations | Supported | Supported |
| Old version API operations | Supported | Not supported by default |
| HTTPS | Not supported | Supported |
| VPC | Not supported | Supported |
| Multi-domain mapping | Not supported | Supported |
| Automatic Alibaba Cloud CDN cache refresh on origin-side updates | Not supported | Supported |
OSS domain names support all IMG features, but you can use only the API operations for the new version. IMG domain names support both the old and new versions of API operations.
To use Alibaba Cloud CDN with IMG domain names, set the origin host to the IMG domain names on Alibaba Cloud CDN. No domain name mapping to the bucket is required.
Bucket behavior by version
Buckets with the old version enabled:
Available domain names are the IMG domain names generated for the old version and any mapped custom domain names.
Old version configurations (such as source image protection) apply only to the IMG domain names, not to the OSS domain name of objects.
Exception: When CRR is enabled, source image protection and the style delimiter are synchronized to OSS domain names.
Disabling IMG on the bucket clears all style configurations and domain name mappings, and the console switches to the new version IMG view.
New buckets or buckets without the old version enabled:
IMG is available by default — no explicit enabling required.
No domain name mapping is needed.
Migrate from the old version to the new version
Old version API operations are not supported in the new version. If your application uses old version API operations and cannot migrate without them, submit a ticket to contact technical support.
If your images are processed only through image styles (not direct old version API calls), migrate with these two steps:
Enable configuration synchronization in the current IMG settings. This synchronizes image style delimiters and source image protection to the new version.
Update your CNAME — if you use a custom domain name, change the CNAME to point to the OSS domain name.