sankeymatic.com

What is SankeyMATIC?

SankeyMATIC is a browser-based tool for building Sankey diagrams — flow charts that show how amounts move between stages, such as a budget breaking into categories, votes shifting across election rounds, or applicants progressing through a hiring pipeline. You type your data as plain lines in the form Source [Amount] Target, then adjust the diagram's appearance with on-screen controls and export the result.

SankeyMATIC

Who it suits

• Analysts and finance staff who want a flow diagram without opening a spreadsheet add-in or design tool.
• Journalists, teachers and students who need a clean graphic for a page, slide or report.
• People who value portability — the page states no installs, no code and no sign-up, and that you can save your work as a readable plain-text file.
• Anyone comparing versions of a diagram, since plain-text source files can be diffed.

What you can produce

The page describes two export routes: a high-resolution PNG at several sizes, and an SVG suitable for embedding in a web page or editing in vector software. The SVG option matters if a designer needs to tweak colours, fonts or labels afterwards; the PNG is simpler when the diagram is finished.

Trade-offs to weigh

• Text-driven input is fast for people comfortable with a simple syntax, but less inviting if you prefer dragging boxes on a canvas.
• Flow diagrams only. Sankey diagrams compare amounts across stages well; they are a poor fit for trends over time (line charts) or part-to-whole snapshots (pie or bar charts).
• Browser-based work means your data lives in the tab and in files you save, so keep your own copies if the diagram is important.

A concrete next step

Sketch your stages on paper first: list each source, the amount, and where it goes. Then try a small version — for example, Salary [4000] Rent, Salary [1500] Savings, Salary [2500] Living costs — and check whether the widths tell the story you expect before adding detail.

If your diagram needs statistical charts rather than flows, a general charting tool may serve you better; SankeyMATIC's strength is the specific job of showing movement between stages.

How do I enter data into SankeyMATIC to create a flow diagram?

Enter each flow on its own line in the simple text format Source [Amount] Target. SankeyMATIC reads that line and draws a band from the source node to the target node, with the band width proportional to the amount.

A minimal example

If you want to show a budget split, type something like:

Income [5000] Rent
Income [1500] Savings
Income [800] Food

The first line sends 5,000 from Income to Rent; the second sends 1,500 from Income to Savings, and so on. Nodes are created automatically the first time they appear, so you do not need to declare them separately. Repeat a source or target name to connect it to multiple flows, and use consistent spelling because matching is by exact name.

Stages and multi-step flows

Sankey diagrams become more useful when you chain stages. For an application process, you might write:

Applications [1200] Screened
Screened [900] Interviewed
Interviewed [400] Offers
Offers [250] Accepted

Each line is a stage-to-stage flow. The same node name can appear as a target in one line and a source in another, which is how SankeyMATIC builds a funnel or multi-round election view.

Practical tips for entering data

• One flow per line; keep the [Amount] in square brackets.
• Amounts are numbers, so totals and percentages are calculated from them rather than typed as labels.
• Use short, distinct node names to keep the diagram readable.
• Save the plain-text source file so you can reopen it later, compare versions, or move it between computers and browsers.
• Export as SVG if the diagram will go into a web page or vector editor, or PNG for a fixed high-resolution image.

If you are unsure where to start, sketch the stages on paper first, then translate each arrow into one Source [Amount] Target line. That keeps the data entry quick and makes the resulting flow diagram easier to read.

What types of visualizations can I make with SankeyMATIC, such as budgets or election results?

SankeyMATIC is built for one specific visual form: a Sankey (flow) diagram, where quantities flow from sources through stages to targets. The site describes these diagrams as a way to "compare amounts through different stages," and its own examples include budgets, financial results, the story of an application process, and elections with multiple rounds. You enter flows as Source [Amount] Target and the tool lays them out as connected bands.

That single format covers more ground than it first appears:

• Budgets and financial results — money entering from income sources, splitting into categories, and draining into savings or expenses.
• Multi-round elections — votes transferring from first-round candidates to later-round winners or eliminated options.
• Application or funnel processes — applicants moving through stages, with drop-offs shown as flows that stop partway.
• Energy, material or traffic flows — anything where a total is divided and recombined across steps.
• Time or cost allocation — hours or spend distributed across projects, teams or activities.

What it will not do is produce bar charts, line graphs, pie charts, maps or free-form diagrams. If your data is a trend over time or a simple category comparison rather than a flow between stages, another chart type will serve you better.

A quick decision test

Ask whether each row of your data has a from, an amount, and a to. If yes, a Sankey diagram fits and SankeyMATIC can render it. If your data is a single value per category, or a value per date, it does not.

Practical next step

Sketch your flows as plain lines of Source [Amount] Target before opening the tool. A budget with three income sources and six spending categories is a manageable first diagram; a 200-row transaction export usually needs grouping first, or the diagram becomes unreadable regardless of how well it is styled. Once the flows look sensible as text, use the interactive controls to adjust layout and colors, then export a high-resolution PNG for slides or an SVG for embedding in a page or editing in a vector tool. The plain-text state file is worth keeping if you expect to revise the diagram later or compare versions.

For a broader set of chart types, general-purpose tools such as Observable or spreadsheet software may suit you better; SankeyMATIC is the right choice when the flow structure itself is the point.

What export formats does SankeyMATIC support for saving my diagram?

SankeyMATIC supports two diagram export formats plus a separate project save format:

• PNG – a high-resolution raster image, with multiple size options to choose from.
• SVG – a vector file suitable for embedding in a web page or importing into a vector graphics editor.
• Plain-text source file – not a picture of the diagram, but a readable file capturing the current state of your work, so you can resume later on any computer or browser and compare versions by diffing the source files.

Which one to pick

A practical workflow: keep the plain-text file as your master, export SVG when the diagram will be resized or further styled, and export PNG at the largest size you need for print or presentations. If you only need one file to send to someone who won't edit it, PNG is the simplest choice.

To try it, open SankeyMATIC, enter flows in the Source [Amount] Target format, then use the export controls once the diagram looks right.

Can I save my work in SankeyMATIC and resume it later?

Yes. SankeyMATIC lets you save your work as a plain text file and reload it later, so a diagram isn't trapped in one browser session.

What that looks like in practice

The page describes saving "the current state of your work in a readable plain text file," which you can reopen on any computer or in any browser. Because the file is plain text, it's also diff-friendly: you can compare two versions of a diagram by looking at the differences between the source files. That's useful if you're iterating on a budget or an application-flow diagram and want to see what changed between drafts.

For finished output, the tool also exports a high-resolution PNG (multiple sizes) and an SVG vector file suitable for embedding in a web page or importing into a vector graphics editor.

A concrete scenario

Say you build a Sankey for a quarterly budget review. You save the plain-text source, export a PNG for the slide deck, and export an SVG for the web version. Next quarter, you reopen the text file, adjust the amounts, and compare it against last quarter's file to see which flows shifted.

Decision criterion

If your main need is a one-off image, the PNG/SVG exports are enough. If you expect to revise the diagram repeatedly or share the underlying data with a colleague, rely on the plain-text save — it's the version you can actually resume and edit.

Next step: open SankeyMATIC, enter a few Source [Amount] Target lines, and save the text file before you start styling, so you always have a recoverable starting point.

Is SankeyMATIC free to use without signing up or installing anything?

Yes. SankeyMATIC is free to use and requires no signup, email address, trial period, browser extension or installation—you open the site and start building. The project does accept voluntary contributions to support development, but that is optional rather than a paywall.

What that means in practice

• A good fit if you need a quick flow diagram for a budget, application pipeline, election rounds or similar staged totals, and you don't want an account or a download.
• You enter flows in a simple line format: Source [Amount] Target. That's the whole data-entry model described on the page.
• Interactive controls let you adjust how the finished diagram looks, so you aren't locked into a default style.
• You can export a high-resolution PNG at various sizes, or an SVG for embedding in a web page or editing in a vector graphics tool.
• You can also save your work as a readable plain-text file, which lets you resume later on any computer or browser and compare versions by diffing the source files.

Where it may not suit you

If you need live data connections, collaborative editing with teammates, or automatic chart updates from a spreadsheet, a no-signup text-input tool is probably the wrong shape for that job. It's strongest for one-off or occasional diagrams you want to produce and export yourself.

A useful next step

Before committing, sketch your flows on paper as source → target pairs with amounts. If your data fits that structure cleanly, SankeyMATIC will handle it well. If it doesn't—say, you need time-series animation or shared dashboards—look at general-purpose visualization tools instead, such as Observable for code-driven charts or Vega for a declarative grammar, both of which involve more setup but offer more control.