Mermaid to flowchart — turn Mermaid into an editable diagram, free

Turn Mermaid into a diagram you can actually edit

Large language models love Mermaid. Ask ChatGPT or Claude for a flowchart, a process, or an architecture sketch and you almost always get a block of graph TD text back. That text is precise and version-controllable — but it is not a diagram you can point at in a meeting, drag around, or hand to a teammate to extend. This free tool closes that last gap: paste the Mermaid, and in one step it becomes a real, editable graph on a canvas.

A free FlowGraph sign-in opens the converter, using the same account screen as the rest of the app. Google, GitHub, and email sign-in return to this converter; company SSO currently returns to the app home, where you can reopen it. After sign-in, everything about the conversion happens in your browser. The Mermaid you paste is parsed and drawn entirely on your own device — nothing is uploaded or stored on our servers for parsing. The source is kept only in that browser tab while you work, never placed in a callback URL. That matters when the diagram describes something you would rather not send to a third party: an internal workflow, a system you are designing, or a decision tree with real names in it.

How to convert Mermaid to a flowchart

1. Copy your Mermaid. Grab it from ChatGPT, Claude, a README, a docs site, or write it by hand. The tool reads flowchart syntax — graph TD, graph LR, and flowchart — which is what assistants emit by default.
2. Sign in, then paste it into the box. Google, GitHub, or email returns to the same converter. Drop the text in, or open a .mmd / .txt file directly.
3. Convert. One click lays out the nodes into a clean left-to-right graph, draws the edges, and carries across every label — including the ones in the |pipe| form on decision branches.
4. Edit it like any graph. Rename cards, re-wire edges, assign owners, add detail, and connect it to the rest of your work. The diagram is no longer a snippet of text — it is a living graph.

What the converter understands

The parser is built for the Mermaid that real assistants produce, so it is forgiving. It reads the common node shapes — rectangles A[Label], rounded A(Label), stadium A([Label]), subroutine A[[Label]], cylinder A[(Label)], diamond A{Label}, and hexagon A{{Label}} — and the directed edge operators, including dotted and thick arrows. Edge labels written as -->|yes| come across as labels on the link. A node that is first mentioned bare and later given a label keeps the label, so the order of your statements does not trip it up.

Anything the tool does not need — subgraph blocks, style and classDef lines, click handlers, and %% comments — is skipped gracefully rather than throwing an error. The goal is that you paste whatever an assistant handed you and get a usable graph, not a syntax lecture.

Multi-hop chains on a single line — A --> B --> C — are expanded into the individual steps, and a node you mention bare before you define its label picks up that label wherever it appears. In practice that means you rarely have to clean up an assistant's output before pasting it: the parser meets Mermaid where LLMs actually write it.

Why a living graph beats a picture

Most "diagram from Mermaid" tools render an image. An image is a dead end: to change one box you go back to the text, edit it, and re-render — and your teammates cannot touch it at all. A FlowGraph graph is the opposite. Every node is a real card. You can:

• rename and recolour cards, and drag them into the arrangement that reads best;
• add or remove edges and relabel the relationships between steps;
• attach owners, inputs, outputs, and notes to a step so the diagram carries the real detail of the work;
• link the diagram to your other canvases, so a process connects to the things it depends on;
• keep extending it with AI once you sign in, turning a first sketch into a maintained map.

That is the difference between documenting a process once and actually running on it. Mermaid is a great way to get a first draft out of an assistant; this tool is how that draft becomes something your team keeps using.

Private conversion, with an honest product preview

The Mermaid parse itself is pure and runs on your device, so your pasted diagram text does not need to leave the browser. The converter now starts at FlowGraph's existing sign-in page; Google, GitHub, and email preserve the ?tool=mermaid-to-flowgraph destination rather than creating a second account flow. Enterprise SSO still returns to the app home. FlowGraph's broader AI product entry is a bounded Free Preview: a verified account receives one no-card AI map preview, and continued AI creation, sharing, and publishing follow the plan shown in the app. You can keep an editable .fgraph safety copy so your data is never held hostage.

Related free tools

If you would rather start from a description than from Mermaid, the AI diagram generator turns plain English into an editable graph. If you work in construction or BIM, the free online IFC viewer opens models in your browser with no upload. And if you want a proven starting point, browse the FlowGraph templates — flowcharts, org charts, decision trees, and construction workflows that open as real graphs. When you are ready, sign in and open the converter.