Hide by Default

Start collapsed, reveal on demand

Sometimes you want outputs hidden until readers actively choose to see them. This keeps pages clean while making details available on demand.

Every output on this page starts hidden. Click the toggle buttons to reveal them.

Configuration

Add output-hidden: true to your settings:

extensions:
  toggle:
    output-toggle: true
    output-hidden: true

Or set it on individual cells with #| output-hidden: true.

Examples

These outputs are hidden until you click:

Example

print("You found me!")

[1] "You found me!"

for (i in 1:3) {
  cat("Line", i, "\n")
}

Line 1 
Line 2 
Line 3 

Source

```{r}
print("You found me!")
```

```{r}
for (i in 1:3) {
  cat("Line", i, "\n")
}
```

Showing Specific Cells

Even when the document default is hidden, you can force specific outputs to show:

Example

print("I'm visible by default, despite the document setting.")

[1] "I'm visible by default, despite the document setting."

Source

```{r}
#| output-hidden: false
print("I'm visible by default, despite the document setting.")
```

Summary

Use output-hidden: true to start outputs collapsed. Readers click to reveal. Override with output-hidden: false on cells that should always show.

Works well for problem sets (hide solutions), reports (hide supporting details), and tutorials (reveal answers progressively).