Use the x-oss-process query parameter to process OSS objects synchronously. OSS returns the processed result directly in the HTTP response — the calling application waits for the result before proceeding. This mode suits low-latency operations such as image processing and document processing.
Supported operations
The x-oss-process value uses the format <category>/<action>,<parameters>. Replace the asterisk (*) in the operation column below with the actual action for your use case. For example, x-oss-process=image/resize resizes an image.
| Feature | Operation prefix | Access methods |
|---|---|---|
| Image processing | x-oss-process=image/* | File URLs, Alibaba Cloud SDK, RESTful API |
| Document processing | x-oss-process=doc/* | Alibaba Cloud SDK, RESTful API |
| Media processing — video | x-oss-process=video/* | — |
| Media processing — audio | x-oss-process=audio/* | — |
| Image intelligence (except decoding blind watermarks) | x-oss-process=image/* | — |
Image processing supports file URLs for anonymous access. Document processing requires authentication — use the Alibaba Cloud SDK or RESTful API with a signed request.
For available actions and parameters, see:
Image processing: IMG parameters
Document processing: Online document preview, Online file editing, Document snapshot
Media processing: Video information extraction, Audio information extraction
Image intelligence: Image intelligence
Combine multiple operations
Chain multiple operations in a single request by separating them with a forward slash (/).
Image processing via file URL
For operations that allow anonymous access, append multiple parameters directly to the file URL:
https://examplebucket.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_300,h_300/watermark,image_cGFuZGEucG5n,t_90This example resizes the image and applies a watermark — both in a single request.
Document processing via SDK
For operations that require authentication, use the Alibaba Cloud SDK and pass the chained parameters to the request:
// OSS SDK for Java: Convert format and capture a snapshot of a document in one request
getObjectRequest.setProcess("doc/convert,target_jpg,source_docx/snapshot,target_jpg,source_docx,page_2");This example converts the document to JPG format, then captures a snapshot of page 2.
What's next
To save processed results as new objects in OSS, see Save As.