SankeyMATIC is described as 'There are no tools to install. There is no code to write. You do not have to sign up for anything'. There are eight alternatives to SankeyMATIC, not only websites but also apps for iPhone, iPad and Windows. The best alternative is SankeyDiagram.net, which is free. Other great sites and apps similar to SankeyMATIC are Sankey Diagram (Paid), Open Sankey (Free, Open Source), Sankey Flow Show (Freemium) and e!Sankey (Paid).
Professional drawing tool to create Sankey Diagrams. These diagrams show flows, where the width is proportional to the rate of flow. The diagrams can be created interactively, adding flow sources and sinks, moving nodes and flows around, editing colors, and more.
Open Sankey is a flow chart tool based on D3.js and php. Primarily developed for visualizing material and energy flows and allows the user to draw a diagram manually starting from a blank page or to load data in the form of supply and use tables.
Online flowchart maker: Sankey Flow Show is a modern online web application running in your browser. It focuses on high graphical quality and user efficiency. Highlights: Revision history, live collaboration, customizable data forms.
Allows you to drag and drop fields from your data to customize the Sankey Flow and dynamically add Filters on any Field in the diagram to squeeze the data. Has automatic highlights of bands across the diagram to highlight data relationships and you can even mix and match colors.