A data flow diagram maker that presents the path data takes
- Free
- No sign-up
- Works offline
Classic DFD notation in your browser — draw it free, press Present, and the diagram walks the route your data travels — narrated, if you like.
Present reveals your data flow diagram one step at a time, on its own.
Diagramium's data flow diagram maker is a free, browser-based editor for classic DFD notation: external entities, processes, data stores, and labeled flows. What makes it different is that a finished diagram can present itself — press Present and it reveals the path data takes step by step, with optional AI voice narration and per-step notes.
The live example on this page is exactly that: a published DFD tracing its own flows. No account is needed to draw, present, or export stills, and diagrams are local-first — they live on your device and in the files you export, never on a server. Once loaded, the editor works offline.
The four elements of DFD notation
A data flow diagram uses exactly four elements: external entities, processes, data stores, and labeled data flows. Everything on the page is one of those four, which is what keeps a DFD readable.
- External entities — the people and systems outside your boundary that send data in or receive it: a customer, a payment gateway, a supplier.
- Processes — the numbered steps that transform data, taking it in one shape and putting it out in another.
- Data stores — data at rest: a database, a file, a ledger. A store does nothing on its own.
- Data flows — labeled arrows naming the data that moves, as a noun ("Order details"), never as an action.
Two rules keep the notation honest: every flow carries a label, and data never passes directly between two stores or from an entity to a store — a process always sits in between.
Level 0 context vs. level 1 decomposition
A level 0 data flow diagram — the context diagram — shows your whole system as a single process, with every external entity arranged around it and the flows that cross the boundary named. It answers one question: what goes in, and what comes out?
A level 1 diagram then decomposes that single process into its major sub-processes, numbered 1, 2, 3, with the data stores between them. The check that keeps the two levels consistent is called balancing: every flow that enters or leaves the parent must reappear at the child level. For a worked example from context diagram to level 1, read how to create a data flow diagram.
Present the path data takes
Pressing Present turns a finished DFD into a step-by-step story: the diagram reveals one element at a time, tracing the route data takes through your system. That is the whole point of the notation — and the hardest thing to get across from a static picture, where a reviewer has to parse twenty arrows at once.
Each step can carry AI voice narration, subtitles with word-by-word highlighting, a spotlight on the current shape, background music, and a "why this matters" note — so the diagram explains not just that "Order details" flows into "Validate order," but why that boundary exists. Hand-drawn themes like Doodle and Handnote are there when a whiteboard look fits the room better than a formal palette.
From blank canvas to shared DFD, step by step
You can go from an empty page to a presented, exported DFD in a few minutes:
- Open the data flow diagram editor. It runs in the browser — nothing to install, no sign-up.
- Place your external entities around the edge of the canvas: every source and destination of data outside the system.
- Add the processes that transform data, and number them.
- Add data stores where information rests between processes.
- Connect everything with labeled flows, naming the data each arrow carries.
- Press Present to watch the diagram reveal itself, and add per-step narration or notes if you want it to talk.
- Export as PNG or SVG — free, no account. A free account unlocks animated GIF, video, and animated SVG exports, and you can also record the live presentation.
Prefer to start from a working diagram? The Explore gallery holds hundreds of editable templates, including narrated explainers.
DFD or flowchart: pick by what moves
A data flow diagram shows where data moves; a flowchart shows the order in which steps happen. That single distinction settles most "which diagram do I need" questions.
A DFD has no decisions, no loops, and no sequence — the commonest beginner mistake is labeling arrows with actions ("send invoice") instead of data ("Invoice"). If you are documenting a procedure with branches and outcomes, draw a flowchart. If you are documenting how information travels between people, systems, and storage — for an audit, a systems-analysis handoff, an onboarding — draw a DFD. Diagramium includes both editors, plus 24 more, in the same free app, so switching notation is never a switch to another app.
Frequently asked questions
Is the data flow diagram maker free, and do I need an account?
Yes — the data flow diagram maker is free, and you need no account to draw, present, or export PNG and SVG stills. A free account unlocks the animated export formats. There is no paid tier.
What formats can I export a data flow diagram to?
PNG and SVG exports are available to everyone with no account. Animated GIF, video, and animated SVG exports unlock with a free account, and presentations can also be recorded live as you play them.
Does the editor work offline, and where do my diagrams live?
Diagrams live on your device and in the files you export — Diagramium is local-first, and no feature uploads diagram content. Once the app has loaded in your browser, the editor keeps working offline.
What is the difference between a level 0 and a level 1 data flow diagram?
A level 0 data flow diagram, also called the context diagram, shows the entire system as one process surrounded by its external entities and the flows crossing the boundary. A level 1 diagram breaks that single process into its major numbered sub-processes and the data stores between them, keeping every boundary flow from level 0 intact.
How is a data flow diagram different from a flowchart?
A data flow diagram maps where data moves between entities, processes, and stores, with no decisions, loops, or step order. A flowchart maps the sequence of actions and decisions in a procedure. Use a DFD when the question is "where does this data go," and a flowchart when it is "what happens next."
Can I embed a self-playing data flow diagram on my website?
Yes — any diagram published in the Explore template gallery can be embedded on another website as a self-playing iframe, so the data flow diagram presents itself step by step right on your page.
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