Is SankeyMATIC free to use, and do I need an account?

Updated

SankeyMATIC is free to use, and you do not need an account to use it. According to the site, there are no extensions to install, no code to write, and you do not have to enter an email address or sign up for a trial period. You can contribute to support its development if you like, but that is optional.

What you can do without signing up

The site is built so you can go straight to making a diagram. Its own description of the workflow covers the main steps:

  • Enter data easily. Flows use a simple format: Source [Amount] Target.
  • Customize interactively. A wide array of controls lets you adjust how the diagram looks.
  • Save your work in multiple ways. You can export a high-resolution PNG at several sizes, export an SVG for embedding in a web page or importing into a vector graphics editor, and save the current state as a readable plain text file.

That plain text file matters if you care about continuity: it lets you resume work later on any computer or in any browser, and it lets you compare versions of a diagram by showing the differences between source files.

What "free" does and does not tell you

The page evidence supports these specific claims:

Question What the site says
Need to install an extension? No
Need to write code? No
Need an email address? No
Need to sign up for a trial? No
Can you contribute? Yes, optionally, to support development

What the available material does not state is a price, a paid tier, or any login requirement. So the safe reading is: the described use of the tool requires no account and no trial sign-up, and contributions are welcomed but not required. If you need certainty about commercial use, storage limits, or future paid features, check the site directly rather than assuming.

When this matters for your task

If you are evaluating SankeyMATIC for a one-off diagram, the no-account, no-install setup means you can test it immediately with a small dataset. If you are evaluating it for recurring work, the plain-text save format is the more relevant feature, because it gives you a versionable source file rather than only an image export.

Sankey diagrams themselves are used to compare amounts through different stages, so they fit things like budgets, financial results, the story of an application process, or elections with multiple rounds.