Multipart upload is well suited for uploading large objects in weak network or high-bandwidth environments. The COS Console and SDKs can break a single object into multiple parts and then upload them. You can also do so by yourself and upload each part through API calls. Multipart upload has the following benefits:
When uploaded, the parts are numbered consecutively. You can upload each part separately or upload them in any order. COS will merge the parts into an object based on their numbers. If the upload of any part fails, the failed part can be uploaded again without affecting other parts and the content as a whole. In a weak network environment, multipart upload is recommended for objects larger than 20 MB. In a high-bandwidth environment, multipart upload is recommended for objects larger than 100 MB.
You can use the REST API directly to initiate a multipart upload request. For more information, see the following API documents:
You can directly call the multipart upload method in the SDK. For more information, see the SDK documentation for the corresponding programming language below: