A free fishbone diagram maker for finding the actual cause
- Free
- No sign-up
- Works offline
State the problem, sort the causes onto bones, then press Present and take a review through one branch at a time instead of all at once.
Present reveals your fishbone diagram one step at a time, on its own.
A fishbone diagram — Ishikawa, or cause-and-effect — is what a team draws when something keeps going wrong and everyone has a different theory. Free, no sign-up, stored in your browser.
Its job is to get every theory onto the page and grouped, so the conversation moves from "I think it is X" to "which of these do we have evidence for?"
The head, the bones, and the categories that go on them
The head is the effect — one specific problem, stated as a problem rather than a solution. The bones are the major cause categories, and each carries the specific causes beneath it.
Manufacturing teams often use the 6Ms — Method, Machine, Material, Manpower, Measurement, Environment. Service and software teams usually do better with categories drawn from their own system: People, Process, Technology, Data, Suppliers. Either way, the categories exist to stop the group listing twenty unsorted causes and calling it analysis.
The technique that makes it work is to keep asking why down each bone until you reach something you could actually change. "Staff were not trained" is a cause; "there is no owner for onboarding material" is the root you can fix.
Write the head as a problem, not a solution
The commonest failure is a head that already contains the answer: "we need a new CRM" is a proposal, and every bone under it will be evidence for a decision already taken. "Sales data is entered twice" is a problem, and the diagram can genuinely explore it.
Be specific too. "Customer churn" is a topic; "churn rose from 3% to 7% in Q3 among annual plans" is a problem with a shape you can trace.
Present one bone at a time
Press Present and the diagram builds from the head outward, one category at a time, narrated. In a post-incident review that keeps the room on one branch until it is finished, rather than jumping between theories.
How to make a fishbone diagram, start to export
Open the editor, write the effect at the head, then add a bone for each cause category. Fill each bone with the specific causes, asking why until you reach something actionable. Export a PNG or PDF for the report, or present it.
Free, private, and offline
Diagramium is free and there is no paid tier. Draw, present and export PNG or SVG without an account; a free account unlocks the animated export formats — GIF, video and animated SVG.
Your diagram is stored in your own browser, not on a server. It keeps working with the network off, and nothing is uploaded unless you choose to publish it.
Frequently asked questions
Is this fishbone diagram maker free?
Diagramium is free and there is no paid tier. Draw, present and export PNG or SVG without an account; a free account unlocks the animated export formats — GIF, video and animated SVG.
What are the 6Ms in a fishbone diagram?
Method, Machine, Material, Manpower, Measurement and Environment — a manufacturing default. For service or software work, categories drawn from your own system (People, Process, Technology, Data) usually surface more.
Is a fishbone diagram the same as root cause analysis?
It is one tool used within it. The fishbone gets every candidate cause onto the page and grouped; deciding which are real still needs evidence, and the diagram is where you record what you tested.
How many bones should a fishbone have?
Four to six categories. Fewer and the sorting does no work; more and the diagram becomes a list drawn diagonally.
When should I use a fishbone instead of a five whys?
Five whys follows a single chain and is fast when the cause is likely one thing. A fishbone is better when several causes may combine, or when a group needs to see all the theories side by side before choosing what to investigate.
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