Object Meta describes the attributes of files uploaded to OSS. These attributes are classified into two types: HTTP standard attributes (HTTP Headers) and User Meta (custom metadata).  File metadata can be configured when files are uploaded or copied.
  • HTTP standard attributes
    Name Description
    Cache-Control Cache action of the web page when the object is downloaded
    Content-Disposition  Name of the object when downloaded
    Content-Encoding Content encoding format when the object is downloaded
    Content-Language Specifies the content language encoding when the object is downloaded
    Expires Expiry time
    Content-Length Size of the object
    Content-Type File type of the object
    Last-Modified Time of last modification
  • User Meta

    This attribute allows you to enrich the description of objects using custom metadata. In OSS, all parameters prefixed with "x-oss-meta-" are considered as User Meta, such as x-oss-meta-location. A single object can have multiple similar parameters, but the total size of all User Meta cannot exceed 8 KB. User Meta information is returned in the HTTP header during GetObject or HeadObject operations.

Set object Meta when uploading objects

You can set object Meta when uploading objects.


You can set object Meta when using multipart uploads.


Modify object Meta after uploading objects

To modify the object metadata without modifying the actual data, using the copy object interface is recommended. In this way, you only need to apply the new metadata in the HTTP header and set the copy source and destination addresses to the current address of the object.


Retrieve object Meta

This feature applies when you must retrieve object Meta, but not the object data.