PUT Object

Creates a new object (via upload, copy, or compose), applies object ACLs, or changes the storage class.

Use a PUT object request to:

• Upload an Object
• Copy an Object
• Compose an Object
• Apply Object ACLs
• Set Object Storage Class

Common request headers

The following are common request headers for PUT object requests.

Header	Description	Required
Authorization	The authentication string for the request.	Yes
Content-Length	The length of the request body without headers (in bytes). * Not required for requests that use chunked transfer encoding.	Yes*
Content-Type	The MIME type of the request body. If you do not specify a content type, Cloud Storage defaults to [`application/octet-stream`](https://tools.ietf.org/html/rfc2046#section-4.5.1) when it serves the object.	No (recommended)
Content-MD5	The MD5 digest of the request message without headers.	No
Date	The date and time of the request.	Yes
Host	The URI for Cloud Storage. For more information, see Request Endpoints.	Yes
Transfer-Encoding	Indicates if the message body was chunked.	No (except for requests that use chunked transfer encoding)
x-goog-if-generation-match	If the generation you specify is the same as the object you're overwriting, then the object is overwritten. You can also specify 0 as a special value to indicate that the new object is only created if there is no existing object.	No
x-goog-if-metageneration-match	If the metageneration you specify is the same as the object you're trying to update, then the object metadata is updated. This is only allowed if x-goog-if-generation is specified. By combining these two generation properties, you can implement safe read-modify-write updates.	No
x-goog-storage-class	Gives an object a storage class besides the default storage class of the associated bucket.	No