Business / Diagrams
Flowchart Maker: Mermaid Preview and Simple Builder
Create a flowchart with Mermaid text and a live preview. Add process, decision, start-end and input-output nodes, connect them with labels, or start from three original templates.
Flowchart Maker: Mermaid Preview and Simple Builder: Write a flowchart in Mermaid text or use the builder to add steps, decisions and connections, and see the diagram update as you type. Start from an example, then copy the text or download the flowchart as SVG or PNG. Runs 100% locally in your browser with zero server file uploads.
- Category
- Business & admin tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Simple builder
Preview updates as you type. The builder appends statements to your text. Configuration directives, custom styles and click handlers are disabled.
Rendering preview…
Flowchart syntax
Mermaid's flowchart language supports nodes, edges and labelled decisions. This tool supports the flowchart part of that language; the builder adds new lines to the end of your text. Official syntax: https://mermaid.js.org/syntax/flowchart.html
Security and licence
Diagrams are drawn in your browser with Mermaid, an MIT-licensed open-source library, in its strict security mode: HTML in labels, click actions and configuration blocks are not allowed, so a pasted diagram cannot run code. Official security setting: https://mermaid.js.org/config/schema-docs/config-properties-securitylevel.html
How to use it
- Choose a process, decision tree or login template, or write Mermaid flowchart text.
- Add a node with the builder, then connect existing node IDs and optionally label the connection.
- Fix any reported syntax errors and download SVG, PNG or Mermaid text.
Privacy & limitations
Mermaid text is processed only in your browser. Nothing is uploaded or saved to local storage. Configuration directives, callbacks, images and external resources are disabled.
Related tools
Frequently asked questions
How does the builder name nodes?
It uses the next unused N-number ID. To connect nodes, enter their IDs from the text. The builder safely encodes quotes, brackets and other label punctuation.
Can I use every Mermaid diagram type?
This tool accepts flowchart or graph syntax only. Use the existing Mermaid editor for other diagram types.
How are errors shown?
Parser errors show a line number when Mermaid provides one. Security and input-limit errors have a separate message.
Are the templates copied from elsewhere?
No. The simple process, decision tree and login flow are original short examples written for this tool.
Free tool · runs in your browser · no account required