# Text editor

The text editor is one surface for every text language. You pick the language, write the source, and see it render as you type.

---

## What you get

* **Live preview.** The diagram redraws as you type.
* **Syntax highlighting** for the language you picked.
* **Errors in place.** A broken line is pointed at rather than silently blanking the diagram.
* **Language switching.** Change language and the source is kept.

![image-20260907-090110.png](https://help.gocapable.com/images/c3a3113b-7d07-4218-9e06-1449385bc811.webp)

## Which language

Around thirty are supported. [Reference](https://help.gocapable.com/diagrams/reference.html) lists them all with what each renders; [Diagram types](https://help.gocapable.com/diagrams/diagram-types.html) recommends one per job.

---

## A few things that catch people out

* Indentation matters in several languages, Mermaid included. A stray space is the most common cause of a blank diagram.
* Some languages render in your browser and others on a renderer service. It affects privacy, not correctness. See [Security and privacy](https://help.gocapable.com/diagrams/security-and-privacy.html).
* If you would rather click than type, Mermaid has a visual editor. See [Mermaid visual editor](https://help.gocapable.com/diagrams/editors.html).

---

## Related

[Mermaid visual editorThe same output without the syntax.](https://help.gocapable.com/diagrams/editors.html)

[ExamplesCopyable source per language.](https://help.gocapable.com/diagrams/examples.html)

[ReferenceEvery supported language.](https://help.gocapable.com/diagrams/reference.html)

---

_Write a line, watch it redraw._