Quarto code chunk options, explained

A practical guide to Quarto chunk options: echo, eval, include, warning, message, output, and the figure options fig-cap, fig-width and label — with a live example.

A Quarto code chunk runs R and drops the result into your document. Chunk options control how — whether the code shows, whether warnings appear, how big a figure is. In Quarto they go on #| (“hash-pipe”) lines at the top of the chunk, one per line.

The shape

```{r}
#| echo: false
#| warning: false
summary(cars)
```

Everything after #| is a YAML setting for that chunk. Here the code is hidden and warnings are suppressed — only the output appears.

The options you’ll use constantly

• echo — show the code? echo: false runs it but hides the source (clean reports); echo: true shows it (tutorials).
• eval — run the code? eval: false displays the code without executing it — handy for illustrating syntax.
• include — include: false runs the code but shows nothing (neither code nor output). Perfect for a hidden setup chunk that loads packages.
• warning / message — false keeps R’s warnings and startup messages out of the finished document.
• output — output: false runs the code and keeps the source but hides the result.

A common pattern — one silent setup chunk, then visible analysis:

```{r}
#| include: false
library(ggplot2)
library(dplyr)
```

Figure options

When a chunk draws, these control the figure:

• label — an identifier starting with fig- (e.g. fig-trend) so you can cross-reference it.
• fig-cap — the caption printed under the figure.
• fig-width / fig-height — size in inches.
• fig-align — left, center or right.

Here’s a real chunk with fig-width: 7, fig-height: 3.5 and a caption — rendered live:

Figure 1: A chunk’s figure options control its caption, size and alignment.

Change fig-width and re-render and the figure resizes — no image editing.

Setting options for the whole document

Repeating echo: false on every chunk is tedious. Set a default once in the YAML header and override per chunk only where needed:

---
execute:
  echo: false
  warning: false
---

Try it live

The code-chunks lesson in our Learn Quarto course lets you toggle these options in a live R console and watch the output change.

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