Which upload parameters are allowed when using unsigned upload?

Below is the list of parameters allowed as the upload parameters of an unsigned upload:

• upload_preset (Mandatory).
• callback.
• public_id.
• folder.
• tags.
• context.
• face_coordinates (image only).
• custom_coordinates (image only).

Additionally, although the public_id parameter can be specified, the overwrite parameter is always set to 'false' for unsigned uploads to prevent overwriting existing files.

Few more functionalities are available via the upload-preset (use original filename, control backup policy, perform moderation, etc.).

Note that unsigned upload parameters cannot contradict the upload-preset settings.