S3 Head Object

HEADhttps://s3.<your-region>.backblazeb2.com/<your-bucket-name>/<your-key>

The HEAD operation retrieves metadata from an object without returning the object itself. This operation is useful if you are interested only in an object's metadata.

AUTHORIZATION AWS Signature

This request is using AWS Signature from collection Backblaze B2 Cloud Storage S3 Compatible API.

Live Read

Backblaze B2 Live Read provides the ability to read data from a multipart object while that object is uploading.

To initiate an upload with Live Read enabled, include the x-backblaze-live-read-enabled HTTP header when using S3 Create Multipart Upload.

To learn more about Live Read, click here.

Using Live Read

You can retrieve metadata about a current Live Read multipart upload when calling Head Object by including the x-backblaze-live-read-enabled HTTP header with the value set to true.

When making a request with either a file name or file versionId, specify a partNumber or a byte range header that includes both start and end values (Live Read only supports a byte range with both values).

Failure to supply either a partNumber or a supported byte range results in a 400 Bad Request error.

When a file name or versionId and a partNumber or supported byte range header are included in the request, but no data is available, a 416 Requested Range Not Satisfiable error response is returned.

See "Live Read Error Codes" below for a complete list of Live Read-related errors.

Live Read Behaviors

The following behaviors are present when Live Read is enabled:

1. The same Live Read Head Object request may return different results over time if the upload process replaces certain part numbers with new versions.
2. A Live Read Head Object request for a byte range may not return the same results as the same Head Object byte range request on the completed object if the upload process does not follow the documented upload part expectations.
3. Live Read-enabled requests that specify a file name but do not specify a versionIdmay switch from one object to another between requests if a new Live Read multipart upload for the same file name is started.
   • The ETag response header value that is returned is not the same as the final ETag value. However, it is consistent across multiple identical calls if none of the parts that are used in the data that is returned from the API call are overwritten with new versions.

HEADERS

PARAMS

PATH VARIABLES

Example Request

curl --location --head 'https://s3.<your-region>.backblazeb2.com/my-bucket-name/object-1'

Example Response

Live Read Error Codes