Mermaid error

Explanatory text above the diagram stops it rendering

Reproduced on Mermaid 11.17.2 · Updated 11 September 2026

Explanatory text above the diagram stops it rendering in Mermaid. The exact parser message, why it happens, and corrected source that renders.

What Mermaid says

No diagram type detected matching given configuration for text: Here is the diagram:
flowchart TD
  A --> B

Why it happens

A sentence from a chat answer sits above the code. The first line is no longer a diagram type, so no parser matches the block.

The source that fails

Here is the diagram:
flowchart TD
  A --> B

How to fix it

Delete everything above the diagram keyword.

flowchart TD
  A --> B

Next steps

Paste your own version into the Mermaid repair tool, which applies this correction and fourteen others and shows every change. The related page covers the surrounding syntax, and the error dictionary lists every message.