The maximum file size which can be uploaded this way is 60 MB - for larger files, you should upload the file data using the standard upload methods, or by passing a remote URL.
Using our Ruby SDK as an example, an upload call which provides a Base64 data URI will look something like this, with a base64 DATA URI as the first parameter to the upload method, which becomes the 'file' parameter of the call to our upload API:
As a specific example that you can try directly, the below code will upload the following PNG image, via its Base64 representation:
If you prefer to generate the HTTP request yourself without using one of our SDKs, note that the data URI must be first url-escaped. For example, using the same image as the example above:
We also have an example of using JQuery on the client side to send an upload from the browser using base64 encoding - for that example, please see the Uploading a Base64 DataURI string of an image directly from the browser article