REST API call with response "413 Request Entity Too Large". What is the size limit?

Hi there,

I have code that call Schedule Campaign with token contains HTML code.  When I made call with almost 800KB of HTML, I received response "413 Request Entity Too Large".  It is fine now after I compressd the HTML using HtmlCompressor to reduce it to less than 600KB.  I would like know what is the size limit of request entity.

Thanks.